The King will tomorrow attend a Catholic Requiem Mass for the Duchess of Kent at Westminster Cathedral. The occasion will mark the first time a reigning monarch has attended a Catholic Mass on U.K ground in a formal capacity since the Reformation.

Katharine, Duchess of Kent, who died last week aged 92, converted to Catholicism in 1994, becoming the first member of the Royal Family to enter the Church since the deathbed conversion of King Charles II in 1685. She was the wife of the Duke of Kent, a cousin of Queen Elizabeth II.