Cromwell was a Roundhead leader against the Royalists in the English Civil War, and became Lord Protector - effectively monarch and PM combined - after the execution of King Charles I in 1649.

and trusted by, The King throughout his exile in Bruges - his father, Charles I, was executed in 1649.

In 1649, King Charles I was put on trial for treason. He was found guilty and sentenced to death. Even though Charles had fought against Parliament, only 59 commissioners signed Charles’ death ...

For a moment, as a new King acceded to the throne, confusion reigned — over his name. The royal formerly known as Prince Charles was first described simply as "the King" in the fateful tweet ...