A common-law tradition and a piece of legislation designed to keep Catholics out of power: these are the legal forces that, even in the present day, outline the arcane rules on who can take the throne of the United Kingdom.
But on Tuesday, prompted by news the Duke and Duchess of Cambridge are expecting a little bundle of joy – and, by extension, a future sovereign – the U.K. government shifted into high gear efforts to reform the system of succession. Deputy Prime Minister Nick Clegg said all 15 other realms of the Commonwealth had committed to passing laws that would stop the practice of favouring men over women in passing along the crown. Legislation to make the change will be submitted to parliament in short order, Mr. Clegg said, but no date has been fixed.
Prime Minister Stephen Harper's spokesman said Canada's government would wait for Whitehall to draft a law before tabling its own.
The reforms will also bring some good news for eligible Catholics hoping to snag a prince or princess: the new rules will allow royals to marry papists without losing their right to inherit the throne.
WHAT IS THE LAW?
The concept of male precedence comes from long-standing common law. Under the current practice, a woman may only inherit the British throne if the monarch has no direct male descendants. This is what happened in the case of the current Queen, whose father, George VI, had no sons.
Before 1689, the other aspects of succession were governed by various declarations, kings' wills and parliamentary decrees. When Richard III usurped his nephews and took the throne in 1483, for instance, his administration had parliament declare the boys illegitimate and not eligible to rule.
In 1543, Henry VIII sought to clarify the confusion caused by his frequent marriages by explicitly spelling out who was to succeed him, and in what order. His son, Edward VI, later tried to do the same in his will, but with rather less success. (His half-sister, Mary, whom he had tried to disinherit, executed his designated successor and took power herself after Edward's demise.)
The current line of succession dates to the Glorious Revolution of 1688, when the Protestant William of Orange invaded England and the Catholic King James II fled. The following year, Parliament gave the throne to William and his wife, Mary II, in the Bill of Rights. That law, along with a second document, the Act of Settlement of 1701, were designed to ensure a Catholic never again sat on the throne.
Among other things, they prohibited anyone who "should profess the popish religion," as well as anyone who married a Catholic, from becoming king or queen. The Act also passed the crown to the heirs of Sophia of Hanover, whose descendents still reign today.
HOW WILL IT CHANGE?
The question of male precedence has largely been a moot point in recent decades: the Queen's oldest child and both his children are male. Only with the prospect of Prince William fathering heirs has the law been questioned.
Because the ruler of the United Kingdom simultaneously inherits the crowns of 15 other countries, Canada included, any change to the succession laws must be endorsed by each one. At a summit in Perth, Australia, last year, the Commonwealth's prime ministers gave their support in principle to a proposal from Prime Minister David Cameron's proposal to allow women to inherit the throne equally.
Since then, the British government has been seeking more concrete assurance that every Commonwealth parliament would support the law before forging ahead.
IS THERE A PRECEDENT FOR THIS?
When Edward VIII abdicated in 1936 to marry Wallis Simpson, each Commonwealth parliament had to accept his resignation and agree to take any of his future heirs out of the line of succession. Given that his decision to marry a divorced woman was, by the standards of the time, a scandalous thing for a king to do, there was little trouble getting political consensus on this.