Polybius uses two terms to describe the extent of Roman power, ἡ οἰκουμένη (‘the inhabited world’) and τῶν ὅλων (‘the whole’), in his account of Rome's rise to hegemony over the Mediterranean. Scholars and translators have treated these two terms as essentially identical, yet this erases a subtle distinction in Polybius’ language. While ἡ οἰκουμένη occurs in a variety of cases, τῶν ὅλων is always in the genitive plural, regularly paired with some noun such as ἀρχή (‘rule’), δυναστεῖα (‘power’), or ἐπιβολή (‘attempt’). Polybius uses the less precise expression, τῶν ὅλων, to refer to objects of the Romans’ own ambitions; ἡ οἰκουμένη describes either the extent of Roman power or the goal towards which fortune, τύχη, directs world events.Footnote ¹ Polybius does not deny that the Romans, like most ancient states, acted aggressively. However, by not using the more exact term to describe Roman aims, he qualifies their agency, making their expansionist tendency an insufficient explanation of their hegemony over the Mediterranean. Moreover, these same passages lack the rich vocabulary that Polybius used to describe deliberation and planning. This re-evaluation of key programmatic passages suggests that they have been over-interpreted in the search for Polybius’ verdict on Roman imperialism.Footnote ²

Polybius uses the more precise term, ἡ οἰκουμένη, fifty-four times in the extant text. Four instances refer merely to inhabited sections of cities and regions, and a further nineteen deal with historiographical concerns and Polybius’ polemic in favour of universal history. Eight use the term in a more prosaic sense, as with an individual's fame covering the world (27.9.7), all the world's reprobates flocking to Nabis of Sparta (13.6.4), or Carthage being the wealthiest city in the world (18.35.9). Twenty-three instances refer to geopolitics and the scope of military activity, nineteen of these concerning Rome.Footnote ³ These include a number of famous programmatic passages which have been frequently interpreted as indicating that world conquest was the Romans’ explicit goal.Footnote ⁴

Despite these passages’ focus on Roman expansion, Polybius often avoids making the Romans the subject of an active verb. This is the case even in the generative question for Polybius’ entire work: ‘how and due to what sort of constitution almost the whole world fell under Roman rule’ (πῶς καὶ τίνι γένει πολιτείας ἐπικρατηθέντα σχεδὸν ἅπαντα τὰ κατὰ τὴν οἰκουμένην…ὑπὸ μίαν ἀρχὴν ἔπεσε τὴν Ῥωμαίων; 1.1.5).Footnote ⁵ The passive participle and the verb both direct the reader's attention less to Roman action than to the magnitude of their dominion. Then in 3.1.4, after finishing his introductory material, Polybius begins his history in earnest by reminding readers of the question of how the world ‘came under Roman dominion’ (ὑπὸ τὴν ἀρχὴν Ῥωμαίων δυναστείαν ἐγένετο), while describing the size of his historiographical undertaking. He also restates this question in the similarly programmatic fragments 6.2.3 and 39.8.7. This formulation of his work's central issue subtly directs readers away from seeking an explanation solely in Roman actions.Footnote ⁶

Four of the nineteen passages referring to Roman subjugation of the οἰκουμένη focus on the agency of τύχη: 1.4.1, 4.2.4, 8.2.4, and 15.9.5. In 1.4.1 Polybius invokes τύχη’s seemingly directed management of affairs as the reason for his own universal history. He then provides a different perspective on the unexpectedness of events in 4.2.4 by attributing the collapse of the geopolitical status quo to τύχη. In 15.9.5 Polybius notes that the victor of the impending Battle of Zama would dominate the world, and then has Scipio Africanus say as much to his troops in 15.10.2. In addition, 21.16.9 and 21.23.4 also credit τύχη or the gods with Rome's power, but are in the voice of ambassadors flattering the Romans rather than the author himself.Footnote ⁷

The relationship between the passages with ἡ οἰκουμένη in which Polybius focuses on the Romans and those in which τύχη takes the dominant role is suggested by Polyb. 8.2. This section begins by contrasting the limited understanding of events that one can gain from a monograph on a particular war with the broader perspective afforded by Polybius’ own synoptic account. He then connects this with the generative question of his work from 1.1.5 by claiming that it is possible to learn ‘in what way in and by means of what sort of constitution fortune brought about the most unexpected result we know’ (τίνι τρόπῳ καὶ τίνι γένει πολιτείας τὸ παραδοξότατον καθ’ ἡμᾶς ἔργον ἡ τύχη συνετέλεσε). The constitution, which Polybius saw as the key determinant of state behaviour, is not the cause of the grand design he finds in Rome's rise to power, but the means utilized by τύχη. Thus, the Romans’ own actions, however indispensable, are doubly subordinated to τύχη in Polybius’ causal scheme.Footnote ⁸

Polybius does make a Roman or Romans the subject of active verbs in four passages (1.2.7, 3.3.9, 3.118.9, and 6.50.6), yet these describe the cumulative result of Rome's success rather than specific policies and actions.Footnote ⁹ In 1.2.6–7, he is not concerned with issues of causation or motive, but with establishing that, unlike the Persians, the Romans have obtained an unassailable position. Rather than the world falling under Roman sway, the Romans themselves ‘have made almost the world subject to themselves’ (σχεδὸν δὲ πᾶσαν πεποιημένοι τὴν οἰκουμένην ὑπήκοον αὑτοῖς). While the middle voice here indicates self-interested Roman action, this participial clause primarily serves to set up the main point, a now garbled statement justifying Polybius’ own enterprise in terms of the magnitude of his topic.Footnote ¹⁰

In 3.3.9 Polybius makes the case that the following narrative shows ‘how the Romans, handling each event, made the whole world subservient’ (πῶς ἕκαστα χειρίσαντες Ῥωμαίοι πᾶσαν ἐποιήσαντο τὴν οἰκουμένην ὑπήκοον αὑτοῖς). This is the most direct attribution of agency among his programmatic statements, yet it makes a subtle distinction between Roman actions and their result. The varied events indicated by ἕκαστα (‘each’) are not necessarily part of a greater plan; in fact, this statement is equally consistent with a narrative in which the Romans expanded opportunistically in a variety of distinct circumstances. This passage could coexist with, or even support, an interpretation in which the Romans actively sought universal empire, but it lacks the specificity to make that claim on its own.

Passage 3.3.9 has a bookend in 3.118.9, which shows how the Romans ‘came into power’ (ἐγκρατεῖς ἐγένοντο). The context of this passage, describing the aftermath of Cannae, makes clear that much of what the historian is thinking about here is how the Romans weathered adversity, and the contrast between their abasement and their eventual success.Footnote ¹¹ In 6.50.7 Polybius posits a disconnect between Roman aims and their result, stating that ‘despite aiming at dominion over the Italians, they quickly subjugated the whole world’ (Ῥωμαῖοι δὲ τῆς Ἰταλιωτῶν αὐτῶν ἐπιλαβόμενοι δυναστείας, ἐν ὀλίγῳ χρόνῳ πᾶσαν ὑϕ’ ἑαυτοὺς ἐποιήσαντο τὴν οἰκουμένην).

One final additional passage, 10.40.7, deserves mention. Here Polybius states that Scipio Africanus, a larger-than-life figure for the historian, brought the greatest and richest parts of the world under Roman power. This is a specific reference to Scipio's campaigns in Spain and Africa, rather than a direct discussion of Rome's hegemony over the Mediterranean.Footnote ¹²

The four references to other powers attempting to dominate the οἰκουμένη offer an illustrative contrast to how Polybius writes of Rome. In 8.10.11 we find the diadochoi fighting ‘over most parts of the world’ (περὶ τῶν πλείστων μερῶν τῆς οἰκουμένης ἀμϕισβητήσαντες). Philip V has vain hopes of world domination in 15.24.6: ‘attempting the greatest deeds and seizing upon the inhabited world with his hopes’ (βαλλόμενον τοῖς μεγίστοις καὶ περιλαμβάνοντα ταῖς ἐλπίσι τὴν οἰκουμένην). In 29.24.1, Polybius also informs us that the Persians, ‘who used to lord it over almost all of the inhabited world’ (οἳ πάσης σχεδὸν τῆς οἰκουμένης ἐδέσποζον), fell slightly short, a reiteration of his statement in 1.2.6. These simple descriptions of attempts at conquest, and the use of more strongly marked words such as ἐδέσποζον (‘lord over’), emphasizes the complexity of Polybius’ deeply layered discussion of Rome's rise to Mediterranean hegemony.

It is the complexity of the Roman narrative that prompts Polybius to emphasize the role of τύχη, yet this is no simple attribution of agency to a supernatural force. Instead, recent work has shown that it is but part of a sophisticated narratological strategy which emphasizes the unexpectedness of Roman hegemony.Footnote ¹³ If Polybius believed the Romans aimed at attaining this position early on, it is highly unlikely that he would present it as such a surprising outcome, particularly to readers already gifted with the power of hindsight.Footnote ¹⁴ This suggests, perhaps, that Polybius used τύχη both to highlight the surprise and because he lacked the conceptual framework to describe emergent processes and the generation of order within chaotic systems. The importance of Polybius’ hesitance to fully credit Roman agency in coming to dominate the οἰκουμένη will become more clear when these passages are contrasted with those in which the historian uses τῶν ὅλων.

Polybius uses τῶν ὅλων more frequently, often paired with words such as ἀρχή, δυναστεῖα, and ἐπιβολή; along with active verbs, these collocations attribute greater agency to the Romans. While he only uses the genitive plural to refer to Roman ascendency (there are no combinations such as τὴν ὅλην οἰκουμένην ‘the whole inhabited world’), comparison with how he uses ὅλος in other forms helps to highlight the meaning of τῶν ὅλων. The phrase τὸ ὅλον can be used adverbially to mean ‘completely’. When used adjectivally, it often pairs with life (βίος), occurs in descriptions of a geographical feature or battle arrangement, or describes the outcome of a whole campaign. Some examples are ‘the whole battle’ (τὸν ὅλον ἀγῶνα; 1.51.11), ‘the whole place’ (τὸν ὅλον τόπον; 6.41.2), and ‘his whole life’ (ὅλον τὸν βίον; 6.39.7).Footnote ¹⁵ The neuter plural τὰ ὅλα is almost always substantive and frequently refers to general results and strategic situations. There are three passages in which τὰ ὅλα is closely correlated with the whole world, but it pertains specifically to the outcomes that made Roman mastery possible.Footnote ¹⁶ After the genitive plural, the dative plural is the next most common case use of ὅλος, with seventy-two occurrences.Footnote ¹⁷ These overwhelmingly indicate decisive results or general situations, as in 6.11.2, where, after Cannae, the Romans were ruined in all matters (τοῖς ὅλοις ἔπταισαν πράγμασιν). The dative plural is also used with verbs such as κινδυνεύω (in the sense of ‘risk it all’).

Polybius uses the genitive plural ninety-nine times, but only twelve of these refer to control ‘of the whole’ in a way that could refer to world domination.Footnote ¹⁸ Most uses of τῶν ὅλων describe a definitive outcome of a battle or campaign, and the general management that led to it.Footnote ¹⁹ In 1.4.1 Polybius describes τύχη working towards its ‘end goal for all affairs’ (τὴν τῶν ὅλων πραγμάτων συντέλειαν). Later on he describes the full power to negotiate that the Carthaginians gave to Hamilcar with ἐπέτρεψαν ἐκείνῳ περὶ τῶν ὅλων (‘they turned over to him [power] over the whole affair’; 1.62.3). In 3.68.12, hopes for prevailing in a battle are portrayed as ‘hopes about the whole outcome’ (τὰς ὑπὲρ τῶν ὅλων ἐλπίδας). Polybius also uses τῶν ὅλων five times to refer to the subject of universal history in his extended methodological polemics.Footnote ²⁰

The salient characteristic uniting these uses of the genitive plural substantive τῶν ὅλων, including the twelve cases of potential world domination, is conclusiveness. Polybius uses it to indicate a decisive result, context determining the exact meaning and extent of ‘the whole’. This interpretation gains further support from two additional passages in which he uses τῶν ὅλων of Perseus’ ambitions, 28.9.7 and 29.7.1.Footnote ²¹ These cases, in which τῶν ὅλων clearly refers only to control of Greece, indicate that τῶν ὅλων’s precise meaning depends on context.Footnote ²² Thus, while τῶν ὅλων seems, at first glance, to signify ‘the whole [world]’, its other Polybian uses show that it refers, with a certain vague generality, to decisive results in specific conflicts.

Of the twelve occurrences in which τῶν ὅλων refers to the whole world, nine describe Roman hegemony, while the rest address Philip V's overweening ambitions at the outset of the First Macedonian War.Footnote ²³ Seven of the nine that deal with Rome refer to a result or state of control, while five describe imperial aspirations. Two of the Roman examples, 1.64.1 and 31.25.7, clearly describe Roman hegemony as a result or circumstance, not a goal. The first, 1.64.1, explains that the Romans, ‘having come to dominate the world’ (κεκρατηκότες τῶν ὅλων), no longer launch such massive fleets as in the First Punic War. The second, 31.25.7, links Roman luxury to the lack of a rival after the Third Macedonian War because ‘they thought that their power over the whole world was unassailable’ (διὰ τὸ…δοκεῖν ἀδήριτον αὐτοῖς ὑπάρκειν τὴν περὶ τῶν ὅλων ἐξουσίαν).

Another passage, 1.3.7, is more ambiguous, for here Polybius states his intent to explain ‘the constitutions of the states that fought over world domination’ (τὰ πολιτεύματα τὰ περὶ τῆς τῶν ὅλων ἀρχῆς ἀμϕισβητήσαντα). Because Polybius elsewhere dates Rome's greater ambitions to the period after the Second Punic War, this passage also seems to describe the result of that war rather than Roman and Carthaginian intent.Footnote ²⁴ Still another passage, 3.4.6, is part of a series of questions that one can ask in evaluating an imperial state, ‘how it administers everything’ (πῶς προεστάτει τῶν ὅλων). While Polybius has Rome in mind, the question itself is more general. The τῶν ὅλων therefore refers to the whole of their empire, not the whole world. The acquisition of that empire is not at issue.

With this overview of the uses of τῶν ὅλων, we are in a position to consider Polyb. 1.3.6, which includes two uses of this phrase that do refer to Roman aspirations.Footnote ²⁵ These instances further highlight the generality of the phrase τῶν ὅλων and illustrate how seemingly authoritative statements on Roman imperialism suffer from compression. Here Polybius tells us that the Romans, having bested the Carthaginians, realized that they had achieved the ‘greatest part of the endeavour (πρὸς τὴν τῶν ὅλων ἐπιβολὴν), then dared to stretch out their hands and take the rest (τὰ λοιπὰ)’. The specificity of this use of τῶν ὅλων to refer to the world derives from its opposition to τὰ λοιπὰ, which Polybius links with crossing in force into Greece and Asia. First, the Romans’ ἐπιβολή remains a theoretical attempt that they did not make until they had almost achieved it. Their decisive act is not to embark upon that quest, but merely to take in hand the remainder. Moreover, the Roman's seizure of these scraps took place through the Second and Third Macedonian Wars, as well as that against Antiochus III, events which Polybius describes in detail and attributes to diverse causes. The Romans acted aggressively and acquisitively, but Polybius’ narrative makes it difficult to see all that follows the Roman defeat of the Carthaginians as part of a uniform policy.Footnote ²⁶ Especially in the opening chapters of his work, we must be careful to not read too much into the compression of forty books of history into a single phrase, however striking.

Not much later, in 1.3.9, Polybius claims that he will make clear with what resources and counsel the Romans ‘embarked upon the endeavours through which they gained mastery of all land and sea near us’ (ὥρμησαν τὰς ἐπιβολὰς διὰ ὧν καὶ τῆς γῆς καὶ τὴς θαλάττης τὴς καθ’ ἡμᾶς ἐγένοντο πάσης ἐγκρατεῖς).Footnote ²⁷ That he then moves on in 1.3.10 to explain that the Romans’ intent (ἐπίνοιαν) and achievement of rule and dominion over all (τῆς τῶν ὅλων ἀρχῆς καὶ δυναστείας) was not unreasonable further demonstrates the inclusivity and generality of the phrase τῶν ὅλων. The contingency of historical events is on display, minus the hindsight which shows τύχη’s guiding hand, when we consider the Romans’ specific endeavours.Footnote ²⁸

Attempts to unify these programmatic passages in which Polybius appears to make decisive and grand statements about Roman imperialism also founder on the reef of chronology.Footnote ²⁹ Because Polybius describes the Romans as undertaking a ‘bid for it all’ (ἐπιβολή τῶν ὅλων), the distinction between his use of τῶν ὅλων and ἡ οἰκουμένη would collapse if he pointed to a single moment at which they undertook this project. However, he depicts the Romans making such attempts on τῶν ὅλων at the end of both the First and Second Punic Wars. It is not possible to reconcile 1.3.6, which points to the aftermath of the Hannibalic War as the moment at which the Romans set out to conquer the world, with 1.63.9, one of the most significant passages for the idea of Roman planning, if τῶν ὅλων refers to the same object in both passages.Footnote ³⁰ In 1.63.9, the Romans take courage from their success in the First Punic War and achieve hegemony: ‘they not only made a daring attempt for power and hegemony over everything, but quickly achieved their goal’ (οὐ μόνον ἐπεβάλοντο τῇ τῶν ὅλων ἠγεμονίᾳ καὶ δυναστείᾳ τολμηρῶς, ἀλλὰ καὶ καθίκοντο τῆς προθέσεως). As already mentioned, because Polybius explicitly makes hegemony the Romans’ purpose (προθέσις), this seems to conflict not only with 1.3.6, which puts the attempt on τῶν ὅλων after the Hannibalic War, but also 2.3.6, where the Romans take up the ‘idea of a bid for it all’ (ἔννοιαν…τῆς τῶν ὅλων ἐπιβολῆς), as the result of victory in the Second Punic War. The solution to this apparent conflict lies in the indeterminacy of τῶν ὅλων: its generality allows these passages to point to any one of a series of critical moments. In 1.63.9 it may imply the end result of Roman imperialism while avoiding a concrete linkage to any specific action. It does not mean that after the First Punic War the Romans explicitly decided to subdue the entire known world.

Polybius also blurs the line between intent and result when he describes the consequences of the Battle of Zama, indicating that explanations of intent were not his concern. In 15.9.3, when he introduces the battle, he notes in his own voice that the Carthaginians were fighting for their own security, the Romans for hegemony (ὑπὲρ τῆς τῶν ὅλων ἀρχῆς καὶ δυναστείας). A far more dramatic statement follows quickly in 15.10.2: Scipio Africanus describes the power that would come from victory as ‘incontestable hegemony and power over the rest of the inhabited world’ (τῆς ἄλλης οἰκουμένης τὴν ἡγεμονίαν καὶ δυναστείαν ἀδήριτον).Footnote ³¹ The proximity of these similar claims necessitates reading them together. Yet, while Scipio describes a future state of power over the rest of the inhabited world, Polybius focuses on the Romans’ reason for fighting.Footnote ³² We cannot take the presentiment of Roman hegemony that Polybius attributes to Scipio as reflective of the author's own understanding of Roman policy.

In addition to suffering from extreme compression, these passages lack most of the rich vocabulary that Polybius uses to describe mental states and the decision-making process, indicating that he was not deeply concerned here with Roman motivations or long-term planning. Like Thucydides, Polybius paid careful attention to vocabulary: a good example is both authors’ insistence on the distinction between ἀρχή (‘beginning’), πρόϕασις (‘pretext’), and αἰτία (‘cause’).Footnote ³³ Here, Pédech's analysis makes clear that Polybius’ understanding of causation is primarily based on the psychology of statesmen and peoples.Footnote ³⁴ He breaks down Polybius’ causal schema into six concepts that occur in order, although not all of these factor into any given explanation. Pédech begins with αἱ προκαθηγούμεναι τῶν κρίσεων καὶ διαλήψεων (‘beliefs influencing choices and decisions’), a phrase drawn from Polyb. 3.6.7 that describes prior assumptions and the terms in which one formulates a problem. These ideas then lead to a goal or project (ἐπίνοια), which in turn is influenced in its implementation by one's διάθεσις (mental state). The goal, filtered through a mental state, generates reasoned-out plans of action (συλλογίσμοι). The sixth element consists of the things ‘through which we come to decide and implement something’ (διὰ ὧν ἐπὶ τὸ κρῖναί τι καὶ προθέσθαι παραγινόμεθα; Polyb. 3.6.8).

Pédech explains Polybius’ use of αἰτία as consisting of mental processes; the ἀρχή, in which Polybius has somewhat less interest, is defined as ‘the first initiatives and acts of things already decided’ (τὰς πρώτας ἐπιβολὰς καὶ πράξεις τῶν ἤδη κεκριμένων; Polyb. 3.6.7). The term used here, ἐπιβολαί (‘acts’ or ‘attempts’), figures heavily in Polybius’ statements of Roman imperialism. It is important to note that ἐπιβολαί (which Polybius sometimes uses as a rough synonym for ἀρχή) are ancillary to his causal explanations.Footnote ³⁵ Many such passages, particularly those involving ἐπιβολαί, actually describe the results of the decision-making process and are not comments on Roman motivations. When, as in his First Punic War narrative, Polybius explores psychological issues such as morale, he presents them as a choice of whether or not to pursue a goal that has already been chosen.Footnote ³⁶ Had he wished to explore these motivations and decisions, we would find the other terms described above with equal or greater frequency in relevant passages.

From this analysis it emerges that Polybius did not use ἡ οἰκουμένη and τῶν ὅλων interchangeably, a fact with significant implications for his analysis of Roman imperialism. The phrase τῶν ὅλων appears as the object of Roman ambition in passages such as 1.3.6 and 1.63.9; however, it does not necessarily refer specifically to the entire world, but instead to the attempt to achieve a decisive result in an arena only imprecisely defined by the author himself. Polybius can then describe the Romans as ‘having come to dominate the world’ (κεκρατηκότες τῶν ὅλων) directly afterwards, as in 1.64.1, presumably thinking of the whole world in a later stage of Roman ascendance, without needing to fully define the extent of Roman dominion at either period. Perhaps τῶν ὅλων points to the Romans’ drive to ‘come out on top’, while not making clear precisely what they would be on top of, when Polybius needs to collapse multiple stages of expansion into a single clause. In contrast, he can use ἡ οἰκουμένη, which refers specifically to the inhabited world, to describe the extent of Roman rule and the historical telos wrought by τύχη, without equating this to a definite Roman initiative.Footnote ³⁷ When Polybius does present attempts to subdue the οἰκουμένη, they are examples of hubristic overreach, as with the schemes of Alexander's successors and Philip V.Footnote ³⁸

Thus, as in many other areas, Polybius uses a precise vocabulary for hegemony. The distinction he makes between τῶν ὅλων and ἡ οἰκουμένη therefore allows him to qualify the Romans’ own agency in achieving dominance over the Mediterranean world. This re-evaluation of Polybius’ hegemonic vocabulary renders his account more coherent. The apparent contradiction between programmatic statements, which can seem to credit the Romans with an explicit programme of world conquest, and the narrative, in which the Romans seem largely reactionary, fades away. By limiting the agency that he attributes to the Romans, Polybius can describe how their aggressive and imperialistic actions resulted in hegemony over the Mediterranean while not crediting them with a degree of long-term planning quite uncommon in the ancient world.Footnote ³⁹