1. I use the term ‘theory’ in its explanatory rather than in its normative sense.

2. As Martin Wight correctly pointed out, the word ‘International’ is an anachronism when used to describe the political structure of medieval Christendom. Contemporary international relations terminology invariably presupposes the existence of a system of states which, in the Middle Ages, had yet to come into existence. Wight, M., Systems of States (Leicester, 1977), p. 130.Google Scholar

3. Strayer, J. R., On the Medieval Origins of the Modern State (Princeton, 1970), p. 83.Google Scholar

4. Beaumanoir, Philippe de, Coutumes de Beauvaisis (Paris, 1900), II, sec. 1673, p. 357.Google Scholar

5. Paris, Matthew, Monarchi Sancti Albani Chronica Majora (London, 1876), pp. 260–261.Google Scholar

6. Homeyer, G. (ed.), Sachsenspiegei (Berlin, 1861), Buch 3, Art. LXXVIII, sec. 2, p. 253.Google Scholar

7. On the nature of medieval ambassadors see: Gondissalvus de Villadiego, Tractatus de Legato, Part I, xv, 25, in F. Pagae (ed.), Tractatus Universi Juris (Venice, 1584), XIII, ii, p. 278; Perrin, J. W., ‘“Legatus” in Medieval Roman Law’, Traditio, 29 (1973), pp. 357–378.CrossRefGoogle Scholar

8. Mattingly, G., Renaissance Diplomacy (London, 1955), p. 26.Google Scholar

9. Chaplais, P. (ed.), Diplomatic Documents Preserved in the Public Record Office, I (London, 1964)Google Scholar, Documents nos. 40, 441, 100, 177–78, 136, 154, 340, 348.

10. Rymer, T. (ed.), Foedera, Conventiones et Acta Publica (London, 1816), I, p. 44.Google Scholar

11. Chaplais, op. cit., Document no. 142.

12. Queller, D. E., The Office of Ambassador in the Middle Ages (Princeton, 1967), p. 12.Google Scholar

13. Rymer, op. cit., I, p. 1011.

14. Dickinson, J. G., The Congress of Arras 1435 (Oxford, 1955), pp. 1–102.Google Scholar

15. Gulielmus Durantis, Speculum Juris, L. Pflugel and G. Laver (eds.), (Rome, 1474), part I, De Legato, sec. 1.

16. Dumont, J. (ed.), Corps Universel Diplomatique du Droit des Gens (Amsterdam, 1726)Google Scholar, I, 1, pp. 78, 116, 150, 152, 164, 202, 206, 198; Rymer, op. cit., I, pp. 30, 760, 370.

17. In the Middle Ages, the term jus gentium meant either the laws that were common to the many different communities of feudal Europe or the laws common to the different communities of the Roman Empire. The first of these two meanings included feudal, mercantile, maritime and ecclesiastical laws. The second did not. In the following discussion I shall only use the term jus gentium in the first of the above senses.

18. Poland was the only important exception.

19. Henrijk of Gorkum, De Justo Bello, prop. 9 in Tractatus Consultatatorii Venerandi Majestii Henrici de Gorychum (Cologne, 1503).

20. Lignano, Johannis, Tractatus de Bello de Represaliis et de Duello (Oxford, 1917), cap. 76, pp. 275–276.Google Scholar

21. See also Johannes Lupus, Tractatus Dialogicus de Confoederatione Principum, in Pagae, op. cit., XVI, pp. 303–8 and Guerreiro, Alfonso Alvarez, Thesaurus Christianae Religionis et Speculum Sacrorum Summarum (Venice, 1559), ch. XLI, pp. 145–154.Google Scholar

22. Isernia, Andreas de, In Usus Feudorum Commentaria (Frankfurt, 1598), Lib. I, tit. 17, p. 29.Google Scholar

23. Gulielmus Durantis, op. cit., Lib. II, Partic. I, sec. 5.

24. ‘Only a prince who does not recognize any secular sovereign may justly wage war… and no subject may wage war without the permission of his sovereign.’ Le Songe du Vergier, 1491, part I, ch. 154.

25. Pisan, Christine de, The Book ofFayttes of Armes and of Chyvalrye (Westminster, 1489), Part I, ch. 3, p. 5.Google Scholar

26. ‘Every state [republica] has the authority to declare and make war. In course of proof of this be it noted that the differences herein between a private person and a state is that a private person is entitled… to defend himself an d what belongs to him, but has no right to avenge a wrong done to him, nay, not even to recapture property that has been seized from him.’ F. Vitoria, De Indis, sec. II, prop. 1, in Vitoria, F., De Indis et de Jure Belli Relectiones (Washington, 1917), pp. 169–170.Google Scholar

27. Loc. cit. Like Vitoria, the Savoyard statesman Pierino Belli (1502–72) argued that only sovereign princes had the right to wage war—although with the qualification that private persons could wage war if they had the permission of their respective sovereigns. Belli, P., De Re Militari et Bello Tractatus (Oxford, 1936), Book II, ch. V, sec. 1, pp. 5–7.Google Scholar

28. Grottos, H., De Jure Belli ac Pads (Oxford, 1925), Book I, ch. IV, sees. 8–14, pp. 156–159.Google Scholar

29. Ayala, Balthasar, De Jure et Officiis Bellicis et Disciplina Militari Libri Tres (Washington, 1912), Book I, ch. II, sec. 7, p. 9.Google Scholar

30. Gentili, A., De Jure Belli Libri Tres (Oxford, 1933), Book I, ch. Ill, p. 15Google Scholar. In 1621, the Spanish Jesuit Francisco de Suarez also forcefully supported Ayala and Gentili's views. ‘A sovereign prince who has no superior in temporal affairs, or a state which has retained for itself a like jurisdiction, has by natural law legitimate power to declare war.’ Conversely, ‘an inferior prince, or an imperfect state or whosoever in temporal affairs is under a superior, cannot justly declare war without the authorization of that superior. A reason, for this conclusion is, first, that a prince of this kind can claim his right from his superior, and therefore has not the right t o declare war; since, in this respect, he has the character of a private person. It is for this reason that private persons cannot declare war.’ F. Suarez, De Charitate, Disputation XIII, sec. 2, in Suarez, F., Selections from Three Works (Oxford, 1944), pp. 805–806.Google Scholar

31. Dumont, op. cit., VI, part 1, CCLIV, p. 480.

32. Pufendorf, S., De Jure Naturae et Gentium Libri Octo (Oxford, 1934), Book VIII, ch. 6, sec. 8, p. 1299.Google Scholar

33. This fear was so great that states often equated embassies from their citizens to foreign princes with the crime of lèse-majesté. ‘It is certain, that subjects, are so far from having a right to send an ambassador o t their own prince, that they cannot without a crime, make a deputation to a foreign prince without the special permission of their sovereign. They who do it, let the pretext be what it will, are guilty of rebellion and high treason.’ A Wicquefort, L'Ambassadeur et Ses Fonctions (The Hague, 1681), I, p. 37.

34. One was sent to England in 1508, but Henry VII refused to receive him.

35. Russell, J. G., Peacemaking in the Renaissance (London, 1986), pp. 138–144Google Scholar; J. G. Russell, ‘The Search for Universal Peace: the conferences at Calais and Bruges in 1521’, in Bulletin of the Institute of Historical Research, XLIV (1971), pp. 1–21.

36. Boerius, Nicolaus, Tractatus de Potestate Legati a Latere in Gallia, in Hrabar, V. (ed.), De Legatus et Legationibus Tractatus Varii (Dorpat, 1905), p. 79.Google Scholar

37. Johannes Bertachinus, Ambasiator (Venice, 1590); Martinus Garratus, Tractatus de Legatis maxime Principum (Venice, 1584); Gondissalvus de Villadiego, op. cit.; Hermolaus Barbarus, De Officio Legati, Bibliotheca Vaticana, Ms. Vat. Lat. 5392, foil. 50–52 V° Nicolaus Boerius, op. cit.; Petrus Andreas Gambarus, Tractatus de Officio atque Auctoritate Legati de Latere (Venice, 1571); Brunellus, Johannes, Tractatus de Officio et Potestate Legati (Paris, 1519)Google Scholar; Doletus, Stephanus, De Officio Legati (Lyon, 1541Google Scholar); Brunus, Conradus, De Legationibus (Florence, 1548Google Scholar). For an excellent discussion of these neglected authors see B. Behrens, ‘Treatises on th e Ambassador written in the XVth and early XVIth century,’ English Historical Review, 51 (1936), pp. 616–27.

38. Rosergio, Bernadus de, Ambaxiator Brevilogous (1436Google Scholar) in Hrabar, op. cit., p. 6. For Rosergio these principals were ‘the greater secular princes, the governments of some cities and the estates of certain realms’—as precise a list of principals as one could sensibly delineate in the mid-fifteenth century.

39. Brunus, op. cit., p. 37.

40. Gentili, A., De Legationibus Libri Tres, II (New York, 1924), p. 11.Google Scholar

41. Hotman, J., L’Ambassadeur, 1603, p. 2.Google Scholar

42. Ibid., p. 3.

43. Grotius, op. cit., Book II, ch. 18, sec. 2, p. 437.

44. Zouche, R., Juris et Judicii Fecialis, sive, Juris inter Gentes (Washington, 1911), II, p. 90.Google Scholar

45. ‘The right of embassy being inseparable from sovereignty, and this sort of correspondence being held only among sovereigns, we must therefore conclude that the Prince or State that receives the Ambassador ought to be sovereign, as well as he that sends him.’ ‘There is no more illustrious mark of sovereignty than the right of sending and receiving ambassadors.’ Wicquefort, op. cit., I, pp. 145, 17.

46. The greatest barrier to the evolution of the idea that only sovereign states have the right of embassy was the imperial princes’ de jure (though not de facto) subordination to the Emperor. This barrier finally was surmounted when the Reichsfürsten were formally allowed to send and receive ambassadors in the Treaties of Münster and Osnabrück. Christophus Besoldus, Themata Juridico-Politica de Legatis et Legationibus (Tubingen, 1622), pp. 9–11; Dumont, op. cit., VI, part 1, ccxliv, p. 480.

47. Rymer, T. (ed.), Foedera, Conventiones et Acta Publica, 3rd edn (The Hague, 1740), IV, part2, p. 181.Google Scholar

48. Dumont, op. cit., II, part 2, xci, p. 143. In 1446, Parliament ratified the act by which Henry VI was released from this obligation. Rotuli Parliamentorum ut et Petitiones et Placita in Parliamento Tempore Edward I, IV, p. 296.

49. In late medieval Sweden, the estates enjoyed the right not only to ratify, but to even vary treaties negotiated by the crown. The collective nature of treaty-making was evidenced by the fact that, up to the end of the sixteenth century, members of the royal council appended their personal seals next to that of the royal council appended their personal seals next to that of the king on all treaties. Ahlund, N., Den Svenska Utrikespolitikens Historia (Stockholm, 1956), I, pp. 75–76.Google Scholar

50. Ayala, op. cit., Book I, ch. VII, sec. 10, p. 83.

51. Jean Bodin, for example, argued that the assassination of Louis Duke of Orleans (1357–1407) was justified on the grounds that he had committed treason by signing a treaty with Henry IV of England. Bodin, J., Six Livres de la Republique (Lyon, 1593Google Scholar), book I, ch. 7, pp. 120–1.

52. Dumont, op. cit., III, part 1, pp. 146, 337, 448; part 2, p. 269. Agreements between a sovereign prince and his own subjects were henceforth called privileges rather than treaties. Felipe II of Spain refused to sign treaties with his Portuguese subjects—insisting on giving them privileges instead. Gentili, De Jure Belli Libri Tres, op. cit., lib. Ill, ch. XVI, p. 379.

53. Ayala, op. cit., lib. I, ch. 7, sees. 4–5, p. 77.

54. Bodin, op. cit., Book V, ch. 6, p. 788.

55. The distinction between the body natural and the body politic of a sovereign prince was extensively discussed in 1562 in the Case of the Duchy of Lancaster. The Commentaries and Reports of Edmund Plowden, I (London, 1816), pp. 212a-13.

56. Ayala, op. cit., Book I, ch. VII, sec. 10, p. 82. Gentili was more equivocal. In answer to the question ‘Is a sovereign prince bound by former treaties,’ he rather curiously argued that they were bound by peace treaties, but not treaties of alliance or friendship. Gentili, De Jure Belli, op. cit., Book III, ch. 22, p. 413.

57. Grotius, op. cit., Book II, ch. XVI, sec. 16, p. 419.

58. Ibid., Book II, ch. XVI, sees. 17–18, p. 420.

59. Pufendorf, op. cit., Book VIII, ch. 9, sec. 8, p. 1338. Pufendorf also made the following distinction between the personal and public agreements of sovereigns. ‘The former are those that are made with the prince with relation to his person and expire with him; the latter are those that are made with kingdoms or commonwealths, rather than the prince or government, and these outlive the ministry and government itself, under which they were first made.’ Ibid., Book VIII, ch. 9, sec. 8, pp. 1337–8.

60. De Jure Belli Hispanorum in Barbaros, prop. 7, in Vitoria, op. cit., p. 169.

61. Kooijmans, op. cit., p. 60. See also: Vitoria, F., De Potestate Civili, prop. 21, in Scott, J. B. (ed.), The Spanish Origins of International Law (Oxford, 1934), p. XC.Google Scholar

62. Bodin, J., Oeuvres Philosophiques de Jean Bodin, in Corpus General des Philosophes Francais, Vol. V, part 3 (Paris, 1951), pp. 72B–73A.Google Scholar

63. The only hint of the modern notion of public international law in Bodin lay in his decision to translate ‘droit des gens’ as jus feciale in the Latin edition of Six Livres de la Republique. Unfortunately, his reason for doing so was never explained or developed. Bodin, J., De Republica Libri Sex (Frankfurt, 1609), Book V, ch. 6, pp. 904–970.Google Scholar

64. Gentili, De Jure Belli, op. cit., lib. I, c. 4, pp. 22–26, lib. I, c. 21, pp. 99–104, lib. II, c. 13, pp. 191–4; Gentili, A., Hispanicae Advocationis Libri Duo (Oxford, 1921), lib. I, c. 25, pp. 117–118.Google Scholar

65. Van der Molen, G. H. J., Alberico Gentili and the Development of International Law (Leyden, 1968), p. 240.Google Scholar

66. ‘The second kind of jus gentium embodies certain precepts, usages of modes of living, which do not, i n themselves and directly, relate to all mankind; neither do they have for their immediate end (so to speak) the harmonious fellowship and intercourse of all nations with respect to one another. On the contrary, these usages are established in each state by a process of government that is suited to the respective courts of each.’ Suarez, op. cit., Book II, ch. 19, sec. 10, p. 349.

67. Brierly, J. L., The Basis of Obligation in International Law (Oxford, 1958), p. 363.Google Scholar

68. Grotius, op. cit., Prologeomena, 1, p. 9.

69. Ibid., Book III, ch. VII, sec. 6, pp. 693–5; Book III, ch. XVIII, pp. 788–91.

70. Hobbes, T., De Give (New York, 1949), ch. XIV, sec. 5, p. 158.Google Scholar

71. A direct corollary of the states becoming the exclusive subjects of public international law was that individuals became the exclusive subjects of civil law and private international law. The former regulated the behaviour of citizens within the territorial jurisdiction of one, while the latter governed the relations between the citizens of different states. The main theorists of this second body of modern international law were Burgundus (1586–1649), Christian Rodenburg (1618–68), Paul Voet (1619–77), Ulrich Hiiber (1636–94) and Jan Voet (1647–1714). von Bar, L., The Theory and Practice of Private International Law, 2nd edn (Edinburgh, 1892), pp. 36–40.Google Scholar

72. Zouche, op. cit., p. 1.

73. ‘Law of [this] kind I choose to describe as “Jus inter Gentes” or law between nations.’ Loc. cit.

74. Mattingly, op. cit., p. 287.

75. Hobbes, T., Leviathan (London, 1973). A Review and Conclusion, p. 391.Google Scholar