[1] Crichton was one of eighteen gentlemen to receive the honour of knighthood at the coronation of King James on 21 May 1424, and was later made a Gentleman of the Bedchamber (Cambellano).
[2][3] In 1426, Crichton, described as a knight and chamberlain (Dominus Willielmus de Chrichton miles cambellanus noster), along with William Fowlis, the royal almoner, and Thomas de Cranston, King's squire, were sent as envoys to the court of Eric III of Norway to negotiate a continuation of the peace between their respective countries.
This brutal incident of murder and betrayal of hospitality has become known as the "Black Dinner" and was an inspiration for the "Red Wedding" massacre in the Game of Thrones series.
[7] Crichton was sent in 1448 to the continent, accompanied by the Secretary of State, John de Ralston Bishop of Dunkeld and Nicholas Otterburn who would latterly assume that position.
The purpose of this embassy was not only to ratify the Auld Alliance between Scotland and France but to find a bride for the as yet unmarried King James.