Though doubtless there will be historians who disagree, I take it – as did the script of the trial – that King John had hitherto behaved in a manner so thoroughly unacceptable as to be termed tyrannical. In giving his judgement, The Hon. Stephen Breyer from the USA cited John Locke’s (albeit anachronistic) assessment that for his subjects to have the right to rebel, a king should be seen to have systematically refused to adhere to the law of the land. Of course no method of testing a king’s behaviour in a court of law existed in 1215, but for his rule to be considered truly tyrannical I think this criterion would be taken as read.

Legal frameworks of the time would have been governed by the weight of precedent, and certainly the judges at our mock trial took the view that John himself had been ‘made king’ by a legal process. This process included religious ceremonial with sacred oath-taking, not only oaths of allegiance but also the coronation oath sworn by the king himself. In consequence of King John’s breaching of the latter, the rebellious barons invoked a long-standing custom and – therefore – legal right known as diffidatio, i.e. they exercised the right of a free man to repudiate his oath of loyalty to his overlord for a justifiable reason. Underpinning this right of diffidatio was the recognition that fealty was a two-way street: that for a subject to keep his oath, the king must do the same.

In our modern age, when promises made are routinely broken, and ‘God-fearing’ is no longer a term to be taken literally, the significance of an oath sworn while invoking the presence of God is scarcely understood and seldom respected: consider the context of judicial process, which is one of the few surviving circumstances when such oaths are still routinely encountered (and routinely flouted). Yet in the Middle Ages, as I have tried to indicate in writings such as my Small Guide to the Great Debate, the process of oath-swearing was one of the pillars of mediaeval society. It was a crucial matter if either party abandoned their solemn oath.

The bonds of this mutual compact defined the relationship between king and subject, already long-established by the 13th century, and gradually developing throughout the ages. It is this promise on the part of the king that is most often forgotten in the cries of ‘usurper!’ that are so widely bandied about in relation to certain monarchs; and it is key to my repeatedly asserted argument that most often the term ‘usurpation’ is a misnomer that merely reflects the prejudices of the person using it.

In pre-Conquest England there was in place a history of election of kings by the Saxon equivalent of Parliament, based on the fundamental requirement of the office to perform a mutually understood function: the defence of the realm and its people. This was gradually extended to include wider responsibilities, notably for the proper administration of justice. In return, the king was entitled to call upon his people to perform whatever was understood to be due to enable him to fulfil such responsibilities. The principle that the king had a duty to perform a job of work continued to be understood for many centuries, and it was only by analogy with succession from father to son in other areas of life that a similar expectation developed in relation to the throne. Although kings often tried to influence who succeeded them, there was never any ‘law of succession’.

Requirements such as embodying the fount of justice as well as the office of leader and commander throw a clear light on crises of succession like the deposition of Edward II, Richard II and Henry VI who fell short of expectations. An even more relevant case is that of the conflict between Stephen and Matilda. Matilda might be the only surviving legitimate issue of Henry I, but his decision to make her his heir was self-serving and ultimately catastrophic: she was not born into an age when a woman could don harness and lead an army in the field. Returning to the mock trial of the barons, a question raised by the presiding judge exemplifies an abiding misapprehension on this point. Why, asked the judge, did the barons in 1215 not choose to replace John with his son, Henry (later Henry III), then aged seven? The question answers itself when you are not blinded by the assumption that the crown was governed by some imagined law of father-to-son succession: in a time of turmoil and civil strife, when the very rule of the land needed to be taken into strong hands, what fool was going to opt for rule by a seven-year-old? That he was later able to succeed upon his father’s death (now aged nine) was principally a function of the abilities and virtues of William Marshal, Earl of Pembroke, his champion and Regent of England.

In 1399 a new dimension entered into the matter of the succession when Henry IV challenged Richard II for the crown and the latter abdicated, rather than defending his right to the death as would have been appropriate to the tradition of the warrior-king. Parliament was drawn into the front line in the disposition of the crown, going through the formal procedure of acknowledging the abdication of Richard and the succession of Henry. The new king is said to have publicly exhibited proof of his genealogy, but the record of the Rolls of Parliament is remarkably non-committal in regard to his descent, and much more specific as to the rewards of his victory over the ruinous former king:

‘In the name of the Father, Son, and Holy Ghost, I, Henry of Lancaster, claim this realm of England, and the crown with all its members and its appurtenances, inasmuch as I am descended by right line of the blood from the good lord King Henry the third, and through that right that God in his grace has sent me, with the help of my kin and of my friends in recovering it, which realm was at the point of ruin for lack of governance and destruction of the good laws.’ [Parliamentary Rolls of Mediaeval England, 1399 Part 1, vol. iii, pp.422-3.] 

Here we have an echo of that same accusation as used by the barons against King John; and despite the fascinating arguments concerning precisely which line of royal descent Henry IV might have claimed, the salient point of this remarkable statement, as accepted and recorded by Parliament, was that God had favoured him in stepping in to avert the ruin of the realm. Had there existed a law of succession which stipulated primogeniture, there was in fact a royal descendant whose claim would have been superior to Henry’s: this was the young Mortimer heir Edmund, Earl of March, then the same age as the son of King John whom we encountered above. Clearly, when the option of the valorous and successful adult Henry was available, there was no support for the claims of a seven-year-old, however senior his line of descent. A child of that age, and one who lacked the support of a strong figure as Regent, ipso facto failed the basic qualification as warlord-cum-lawgiver. 

It is also noteworthy that the childless Richard II, knowing that the succession to the crown was being eyed by his several uncles, had kept them guessing by naming alternative heirs at different times: another indication that primogeniture was not regarded as the primary criterion. Henry IV, once on the throne, tried to secure the succession to his line by statutory enactment in Parliament, but the view of Stanley Chrimes (in English Constitutional Ideas in the Fifteenth Century, p.24) is that this was merely declaratory and did not determine the line of succession: it recognized but ‘did not create’ Henry’s title. By the same token, it made no general provision for a public law of succession.

Only in 1460, when Richard, Duke of York came to press his claim to the throne in opposition to Henry VI, was the emphasis on primogeniture brought to the fore. York’s claim depended on it wholly – it rested on his sharing the same senior line of descent as the Mortimer heir disenfranchised by Henry of Lancaster sixty years earlier. And although Parliament made several attempts to avoid passing judgement on the matter, when forced to reach a conclusion they decided in York’s favour. There were, of course, excellent reasons for striking the bargain that reduced Henry VI to a cipher, since his inept and compliant rule had bankrupted the crown and allowed England to degenerate into a smouldering civil war.

In the case of Henry IV, could the word ‘usurpation’ be applied? The historically literate answer is no. In 1399 Richard II had abdicated rather than defend his crown to the death, effectively abandoning the throne to the judgement of Parliament which accepted Henry of Lancaster’s argument that God had helped him rescue the realm from misgovernment and lawlessness. This echoed the complaints of the Magna Carta barons, namely that the king had resiled from his sacred oath to fulfil his responsibilities to his subjects. So by these standards, and as accepted by Parliament, Henry IV cannot be named a usurper in terms of the legal structure of the day.

It was only in 1460 that Richard, Duke of York secured a decision by Parliament which established primogeniture as an acknowledged criterion for the succession. How this criterion was applied in hindsight to the Lancastrian succession raises a thicket of legal questions, the untangling of which would take someone more expert in jurisprudence than me. Clearly York’s argument was that the first Lancastrian king was a usurper, and his statement to Parliament went into extensive genealogical detail to disprove Henry’s fanciful tale that his mother’s line of descent from Henry III was senior to the line of Edward III and Richard II. However, to this inexpert observer it seems that the Parliament of 1460 stopped short of disallowing the legitimacy of the Lancastrian dynasty, which fits with their desire to reach a compromise with Henry VI. It would have been simpler, and in hindsight would have prevented much unrest and loss of life, if they had declared him a scion of a usurping line, but that would have meant deposing him. Perhaps their legal advisers balked at the idea of retrospective legislation. And York himself had always vowed himself Henry’s true subject. Whatever their reasoning, an accommodation was cobbled together which permitted Henry to keep his crown on condition that York was acknowledged as his heir apparent. I am tempted to suppose that the Lords in Parliament recognized that Henry’s mental capacity was dubious, and that it would be unrealistic to hold him to oaths he had sworn as a child which he probably no longer remembered or comprehended. Whichever way you look at it, although York’s claim of primogeniture was accepted, the deal of 1460 was unique to the prevailing circumstances; it could scarcely be regarded as a precedent, and indeed it permitted the line of Lancaster to cling to the view that theirs remained the rightful royal house of England.

Thus Parliament had signally failed to grasp the opportunity to codify any law that stipulated primogeniture (or anything else) as a qualification for the succession. As Stanley Chrimes commented, ‘It does indeed seem that no such public law existed. In the absence of a direct and competent heir, politics, not law determined the succession. Hence both judges and commons avoided the topic.’ [Op. cit. p.22.] 

The effect was that however the royal family’s internal issues were decided, whether by themselves or by any outside agency, the situation remained as it was in 1215: that he who took on the sworn obligations of kingship would be held to account for how he performed them. And if he should be adjudged deficient, it was not usurpation but a necessary service to the kingdom to remove and replace him.

* https://www.youtube.com/watch?v=8MU7tK6HM3Q. For those of us who have crossed swords in the past with James Eadie, QC, there was a particular piquancy to his defeat on this occasion.