It is easy to characterise the politics of Tudor England simply as religio-political tyranny: easy partly because it is pretty close to the truth, and partly because the Tudor tyrants still have some of their old charisma and fascination. But it has never been adequate. These two books worry away fruitfully at explaining exactly how the Tudor polity worked, and at how its subjects believed it ought to work.

Daniel Eppley's book, essentially a work of political philosophy, tackles a problem which the Tudor state did its best to evade. What exactly did the doctrine of the royal supremacy mean, and, in particular, what were its limits? Neither Henry viii nor any of his successors ever defined it precisely. (That omission was surely deliberate, a point which Eppley might usefully have addressed.) The particular problem which concerns Eppley is the definition of doctrine. As he argues, since the royal supremacy was itself a doctrine, it might be assumed to imply royal authority to interpret Scripture and define doctrine authoritatively. But that claim was so explosive that almost no one was ever willing to make it in theory, or to test it too far in practice.

For, alongside the many biblical proof-texts marshalled to defend the supremacy, stood Acts v.29: ‘We ought rather to obey God than men.’ As Eppley points out – somewhat laboriously – this text as usually applied holes the royal supremacy below the waterline, by elevating the individual conscience above all human authority. And so he sets out to prove that this doctrine turns William Tyndale, Stephen Gardiner, John Whitgift and other supposed advocates of royal supremacy into its opponents – in strict logic, if not in mood.

Only two scholars, Eppley's heroes, managed to solve this conundrum, although (from a monarch's viewpoint) their solution was worse than the cure. Christopher St German and Richard Hooker both arrived, independently (Eppley can do no more than postulate a faint connection), at the argument that the crown in parliament may determine doctrine in such a way as to compel its subjects' consciences. The bulk of the book is devoted to demonstrating this claim, which, especially in St German's case, requires some careful textual work: but the readings of both men are convincing.

A valuable book, then, albeit given a slightly queasy quality by Eppley's evident admiration for the absolutist stance he finds in St German and Hooker. Reacting, perhaps properly, against imposing modern concepts of liberty on the sixteenth century, Eppley is openly sympathetic to attempts to compel religious uniformity. At times he can read like an apologist for Tudor tyranny – or at least for Hooker's subtle, pragmatic and liberal form of it.

Hooker is, oddly, missing from John McDiarmid's edited collection, The monarchical republic of early modern England. The starting point for this volume is a groundbreaking 1987 essay by Patrick Collinson, which suggested that Elizabethan England could usefully be thought of as a monarchical republic. The concept has been very widely accepted and its interpretation vigorously contested. Most of those contests are laid out for us to see in this volume.

So we have disagreements over how republican a monarchy this was: Markku Peltonen sees an almost revolutionary republicanism fired by a ‘democratic conception of rhetoric’, while Johann Somerville pours cold water on the whole concept, dismissing much supposedly republican talk as empty Latinate truisms. Peter Lake, while ostensibly setting out to defend Collinson's original argument, comes close to demolishing it, by pointing out that the queen herself was no republican, and that in the end she won.

The roots of Elizabethan ‘republicanism’ are found variously in humanism, Protestantism or the common-law tradition. McDiarmid's own article parallels views on the development of language and of the state, suggesting that both were understood as emerging through processes of consent (and parliamentary consent at that). Stephen Alford's beautifully written piece on William Cecil sees the monarchical republic's contradictions embodied in him, and in the process reminds us why Alford (and so many others) have fallen under Cecil's spell. And Scott Lucas's essay on the Mirror for magistrates suggests that this was less a human republic than a divine monarchy – even if in practice those are the same thing.

Two scholars pick up a neglected strand in Collinson's original argument, which discerned a localist, communitarian form of republicanism: Richard Cust has a fine case study of this, while Ethan Shagan's piece on the tensions between local (common-law) and Westminster (humanist) republicanism is a superb article, the study of ‘popular politics’ at its best.

Several scholars try to extend the concept chronologically from its Elizabethan base. Anne McLaren sees republicanism at bay under James i; Quentin Skinner locates the ‘real’ monarchical republic after 1688. More interesting (for me, at least) is the concept's prehistory. Dale Hoak's fascinating article looks at its development under Edward vi, in the thought of William Cecil and Thomas Smith, although much of his argument hangs on a less-than-conclusive argument that Smith was the true author of a 1548 tract published under another name.

I would have liked to see more on this side of the question. In the light of Andy Wood's work, the 1549 rebellions seem likely to have been an important part of this story; they are neglected in this volume. So too is the reign of Henry viii: hardly a republican, but a monarch whose reign provided Tudor politics with most of its formative traumas. (As Scott Lucas's essay argues, much republican talk was driven by fear of tyranny.) As Eppley would remind us, St German and Thomas Starkey (to say nothing of Thomas More) were as republican as their Elizabethan successors.

Collinson himself provides a typically rich and playful afterword to the volume, engaging with some of the criticisms his ideas have received, and also providing some criticisms and reinterpretations himself. This is in character, but he can afford to be generous. This volume shows how far his work continues to set the agenda for, and to enrich, the study of Tudor politics and religion.