Charles III was crowned at Westminster Abbey two years ago today. Much tradition is bound up with the coronation, but how much of it is binding on the monarch, and what elements of it can his successor do away with, should he wish? In this post, Carolyn Harris and Philippe Lagassé outline the difference between a constitutional convention, which is considered to be constitutionally binding, and custom and practice, which are not. They discuss how Charles III’s coronation differed from those of his predecessors, before looking forward to the coronation of the next monarch and how the current heir to the throne might also do things differently, should he become king.

The second anniversary of the coronation of King Charles III offers an opportunity to reflect on the importance of the event. Whilst the coronation is clearly a ceremony infused with tradition and religious significance; it is also a constitutional moment. As we recently argued in The Political Quarterly, core elements of the coronation serve a constitutional function that remains important today, however antiquated they may appear to be. Indeed, the coronation’s constitutional purpose arguably explains why critical parts of the ceremony have endured into the 21^st century.

Although core parts of the coronation are constitutional in nature, the ceremony is not a creature of parliament, in contrast to the royal succession, which is determined by legislation dating back to the 1701 Act of Settlement.  Instead, the coronation ceremony flows from the nature of the Crown in the British constitution. As with many aspects of the Crown and the constitution, the coronation operates according to unwritten rules, insofar as they are not codified in a legally binding document.

The unwritten rules of the British constitution are often termed conventions. The term is used fairly loosely to refer to those rules that are not codified or that lack a statutory footing. Yet not all unwritten rules should be properly understood as conventions. There are two other types of unwritten rules that look like conventions but are distinct from them. These rules are practices and customs. When analysing the unwritten rules that surround the coronation, it is useful to appreciate the difference between convention, practice, and custom.

What is a constitutional convention?

As explained by Ivor Jennings, unwritten rules must meet a three-part test to rise to the level of a constitutional convention. First, there must be a ‘reason for the rule’. Put simply, the rule must be nested in a constitutional purpose of some sort. The reason may be tied to a constitutional principle, such as the principle of democracy or parliamentary sovereignty. It may also be connected with a more practical constitutional consideration, such as distributing power between institutions and actors. Still others may serve to give life to an overarching constitutional norm, which is why conventions have been described as a form of constitutional morality. What matters is that there is an underlying constitutional rationale for the rule.

Jennings’ second criterion holds that conventions must be supported by ample precedents. A rule that has only recently been introduced is unlikely to count as a convention. A convention needs time to properly take root and be well-defined and understood by constitutional actors. New rules that are simply declared to exist may have a rationale behind them, but they will not automatically become conventions until they have proved their worth and importance. Indeed, the haste to declare any unwritten rule a convention, even in the absence of well-worn precedents, helps explain why there is skepticism toward the usefulness of the concept. Newly introduced rules may not last beyond the circumstances of their inception or they may be ignored. When these circumstances occur, it does not mean that convention has been violated; it simply means that the new rule never attained the level of convention to begin with, since it failed to become well-anchored by successive precedents. Only those unwritten rules that have been respected over time and have many precedents to back them up should be termed conventions.

The third criterion set out by Jennings holds that conventions are understood as binding by constitutional actors. This criterion reflects the power of the other two. A rule whose rationale is considered sufficiently compelling is likely to accepted as binding. Similarly, a rule that enjoys consistent precedents will have a greater chance of being seen as binding by different constitutional actors. Yet not all rules will be truly binding. If a rule could be easily abandoned without much opposition, then it is not a convention, but some other kind of rule.

Practices and customs

An application of Jennings’ test allows us to distinguish between conventions, practices, and customs. Practices are unwritten rules that have a constitutional rationale but lack sustained precedents and widespread acceptance that they are binding. For instance, the rule that the House of Commons must approve international military deployments is a practice, rather than a convention. The rationale for the rule is clear: the legislature’s support should be secured before deploying the armed forces overseas. Yet the rule lacks clear precedents and is not considered truly binding. Over time, the practice of securing the Commons’ approval for international military deployments may become a convention, as successive precedents better define the contours of the rule and constitutional actors believe that they must abide by the rule. At the moment, however, the practice is merely auditioning to become a convention.

Customs face the opposite challenge. They are rules that have strong precedents and are considered binding by tradition but lack a compelling constitutional rationale. In some cases, customs are conventions from a previous era whose reasons are no longer relevant. For example, the rule that the monarch does not enter the Commons was once supported by a strong reason: the Crown had threatened MPs with arrest leading up to the Civil War and it was essential to protect the chamber from similar transgressions. Today, this rationale has fallen away. With the advent of responsible government, the executive sits in the Commons and the Crown poses no threat to members. Nonetheless, the rule that the Crown does not enter the Commons continues to be followed in the United Kingdom because of centuries of tradition. We know, however, that this rule could be jettisoned with relative ease by looking at unicameral legislatures in other Westminster states. In the absence of a second house, these unicameral legislatures allow the Crown to enter the chamber to give the speech from the throne. Unlike conventions, the absence of a compelling constitutional rationale makes customs vulnerable to relatively simple abandonment.

Using Jennings’ criteria, we can therefore differentiate between conventions, practices, and customs based on the presence or absence of a compelling reason, precedents, and binding acceptance.

Rule	Present	Weak or absent
Convention	Reason, precedent, binding
Practice	Reason	Precedent, binding
Custom	Precedent, binding	Reason

The coronation process: convention, custom or practice?

With this typology of unwritten rules established, we now turn to the specifics of the coronation. We find that the coronation contains all three types of rules, with the core aspect of the ceremony being conventions, more recent additions being practices, and the less salient elements being customs. In 1973, Elizabeth II attended a ceremony at Bath Abbey commemorating the 1000^th anniversary of the coronation of the Anglo-Saxon king, Edgar the Peaceable. The coronation service written by Dunstan, Archbishop of Canterbury in 973, included the presentation of the monarch to the people, an anointment with holy oil, an investiture with royal regalia, a coronation oath, acts of homage and the crowning of the queen consort. These aspects of the ceremony continue to be central to the coronation service in the 21^st century, forming established constitutional conventions. For the coronation to achieve its constitutional purpose of confirming the new reign, it must be highly visible to the public so that there is no question concerning the identity of the new monarch. The legitimacy of the royal marriage is reinforced by the crowning and anointing of the queen consort.

The crowning and anointing demonstrate the dual religious and secular roles of the sovereign as Supreme Governor of the Church of England and constitutional monarch of the United Kingdom, Commonwealth realms and other territories. The importance of the crowning and the anointing to the constitutional legitimacy of the coronation is demonstrated by the determination of previous monarchs not to proceed with the ceremony unless these rituals were performed in their entirety. Charles II commissioned new regalia after the restoration of the English monarchy in 1660 and his coronation did not take place until this regalia was present in 1661. Edward VII rejected a suggestion to reduce the length of the anointing ritual after his coronation had been postponed in 1902 so that he could receive an emergency operation for appendicitis. The number of attendees paying formal homage to the monarch has varied over time but some form of ceremony of this kind remains part of the coronation to the present day. At the coronation of Charles III, the Prince of Wales (Prince William) and the Archbishop of Canterbury, Justin Welby, paid homage to the sovereign, emphasising the monarch’s dual secular and religious role.   

The coronation of Charles III introduced new practices that may become conventions to reflect the monarch’s role as head of a diverse Commonwealth of 56 countries including, at the time of writing, 14 realms in addition to the United Kingdom. As Prince of Wales, the future Charles III championed interfaith dialogue and his inclusion of a wide range of faith leaders at his coronation will likely continue to take place at future coronations. The prominence of the Commonwealth delegations at the coronation of Charles III and the display of an anointing screen showing the names of all the Commonwealth countries may also become an established practice if future monarchs are also Head of the Commonwealth and sovereign of multiple Commonwealth realms.       

While each coronation ceremony draws upon centuries of custom, the individual customs that are retained reflect the personality and priorities of each successive monarch as well as the political and cultural circumstances of their times. Over the past 200 years, public opinion and media scrutiny of coronation ceremonies have played an important role in adapting certain customs for a mass audience and abandoning other customs altogether. The accession of William IV in 1830, following the unpopular reign of his older brother, George IV, brought an end to numerous coronation customs including the serving of a lavish coronation dinner to prominent guests in Westminster Hall and the hereditary King’s (or Queen’s) champion challenging anyone who contested the legitimacy of the new reign to trial by combat. The public censure directed toward George IV for his extravagance during the economic depression that followed the end of the Napoleonic Wars prompted his successor, a former naval officer who had much simpler tastes, to bring an end to certain customs that were important to the public image of medieval monarchs but appeared to be superfluous to the 19^th century constitutional monarchy. William IV also rejected George IV’s efforts to introduce new customs such as guests involved in the ceremony wearing costumes inspired by Tudor and Stuart era fashions. This distinctive attire remains unique to the coronation of George IV.

In contrast, Elizabeth II’s decision to allow her coronation to be televised may have reinforced certain customs in the popular imagination, shaping expectations regarding the setting of the coronation. Since the crowning of the last Anglo-Saxon king, Harold II, in 1066, the location of the coronation has been Westminster Abbey in London. Henry III had his first coronation at Gloucester Abbey in 1216 due to the circumstances of the First Barons’ War but he clearly considered this ceremony to be insufficient as he requested papal permission for a second coronation at Westminster Abbey in 1220. While there is no constitutional reason why the coronation must occur in a particular place, the televising of the coronation may have reinforced this centuries-old custom by showcasing the setting of the ceremony for a global audience.

The current Prince of Wales shares William IV’s disinterest in unnecessary royal ceremonies. While the future kings Edward VIII and Charles III participated in a public investiture as Prince of Wales in 1911 and 1969 respectively, Prince William received the title of Prince of Wales in 2022 without a formal investiture. The transition from the reign of Charles III to that of William V will therefore likely result in a shorter, simpler ceremony with fewer of the centuries-old customs associated with coronations. Constitutional conventions as well as practices that reflect the social and cultural conditions of the 21^st century, however, will continue to be present at future coronations.  

About the authors

Carolyn S. Harris is a historian, author, royal commentator and instructor in history at the University of Toronto School of Continuing Studies.

Philippe Lagassé is associate professor and Barton Chair at Carleton University, Ottawa, Canada.