That’s the year when Prince William—who’s next in line after his father to become king of England—married Kate Middleton, now the Duchess of Cambridge. Middleton’s great-grandfather came from a family of coal miners and her parents were airline workers who wound up making a fortune as founders of a party-supply business. But the tradition of British royals marrying persons lacking noble lineage goes back much further than that.

In 1464, Elizabeth Woodville, a commoner and widow, secretly wed King Edward IV. She was queen consort until her husband’s death in 1483. In 1660, another commoner, Anne Hyde, married the future King James II (then known as James, Duke of York) after becoming pregnant. Anne died in 1671, before James was crowned king in 1685.

Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge following their marriage at Westminster Abbey on April 29, 2011. (Credit: Dave Cannon/GP/Getty Images)

Under the Royal Marriages Act of 1772, all descendants of King George II were required to get the monarch’s permission before tying the knot. The act came about because George III (the grandson of George II) was infuriated his younger brother, Prince Henry, had wed a commoner the king considered unsuitable, Anne Horton, the widow of another commoner.

In 1955, Princess Margaret ended her relationship with a man she hoped to marry, Captain Peter Townsend, because her older sister, Queen Elizabeth, wouldn’t sanction the union. The Church of England, of which Elizabeth is the head, frowned on divorce. However, half a century later attitudes had changed and the queen gave her son, Prince Charles, her official blessing to wed divorcee Camilla Parker Bowles.

In 2013, the Succession to the Crown Act repealed the Royal Marriages Act and made it a requirement for only the first six people in line to the throne to get the sovereign’s consent before marrying. After Prince Charles and Prince William, that list currently includes William’s two children (Prince George and Princess Charlotte), followed by his younger brother, Prince Harry, then his uncle, Prince Andrew.