He was born at Inverugie Castle near Peterhead, the second son of William, 9th Earl Marischal of Scotland.
By the mid-14th century the estate of Inverugie had passed to the Keith Earl Marischals who had their main seat at the coastal fortress of Dunnottar Castle.
He was created Knight Marischal of Scotland upon Charles II return, and in 1677 was created Earl of Kintore along with the subsidiary title of Lord Keith of Inverugie and Keith Hall.