Charles I's third child, and eldest daughter – Mary, the Princess Royal – married William II, Prince of Orange. Their only child, William III of Orange, was fourth in line to the English and Scottish thrones in 1677, when he married his first cousin Mary (daughter of the Duke of York – later King James II). Charles opposed the alliance at first, preferring that Mary should wed the French Dauphin Louis, which would have strengthened the odds of an eventual Catholic successor in Britain; but he later approved it, under pressure from Parliament and with a coalition with the Catholic French no longer politically expedient. Mary's father agreed to the marriage, after pressure from chief minister Lord Danby and the King, who hoped (vainly, as it turned out) that it would improve James's popularity among the Protestants. When James told his 15–year–old daughter that she was to marry her cousin (aged 26), she is said to have "wept all that afternoon and all the following day".
Mary suffered a miscarriage soon after the marriage, and this may have permanently impaired her ability to have children. For whatever reason, she remained childless; she died in 1694, aged only 32, and when William died eight years later (aged 51) the throne passed to Mary's sister Anne.
© Haydn Thompson 2021