It sounds like the plot of a historical drama rather than a modern monarchy concern: a reigning monarch dies suddenly, leaving behind a pregnant consort and a kingdom unsure of who the next sovereign will be. Yet this precise scenario has long been anticipated within the framework of British succession law, and the rules to address it are surprisingly clear.
Established through centuries-old statutes like the Bill of Rights (1689) and the Act of Settlement (1701), the rules of royal inheritance follow a carefully defined path. With the passage of the Succession to the Crown Act 2013, gender no longer determines who inherits first – the eldest child, whether male or female, is now the rightful heir.
But there’s one exceptional circumstance written into the law: the possibility of an heir who has not yet been born. Known historically by the legal term heir en ventre sa mère (literally “in the mother’s womb”), an unborn child is legally acknowledged as a potential monarch if the reigning sovereign dies while their consort is expecting a baby. This principle is in place to maintain constitutional order and safeguard legitimacy in uncertain times.
In practice, if a monarch dies without surviving children but leaves behind a pregnant spouse, the next adult in line – perhaps a sibling or another close relative – would be proclaimed sovereign. However, their reign would be provisional, pending the outcome of the pregnancy. Should the child be born alive, they would immediately become monarch from the moment of birth, taking precedence over the temporary ruler.
In such a case, the provisional monarch would step aside, reverting to their previous title and most likely becoming regent for the newborn king or queen until they reach the age of majority. This process is outlined in existing laws, such as the Regency Act 1937, which provides a framework for delegating royal duties if the sovereign is a minor or otherwise unable to rule.
If the pregnancy ends without the birth of a living child, then the provisional monarch would continue on as the rightful ruler, and the succession line would proceed as usual.
Though this situation has never occurred in recent royal history, it was a real concern in the 19th century. When King William IV died in 1837, his niece Victoria ascended to the throne. Had his widow, Queen Adelaide, been pregnant at the time – a possibility that was considered – it could have postponed or altered Victoria’s accession entirely.
While the notion of an unborn monarch might seem far-fetched, British constitutional law allows for such eventualities. Parliament would likely step in to manage the situation, potentially forming a regency council to oversee the monarchy’s functioning during this period of uncertainty. Though the child would not be crowned for many years, they would legally become sovereign the moment they entered the world.
This little-known provision is more than just an odd legal curiosity – it stands as a testament to the monarchy’s resilience. Even in the most uncertain circumstances, when the throne is vacant and its next occupant has yet to be born, the continuity of the Crown remains protected.
