The title of Earl of Cambridge was created several times in the Peerage of England, and since 1362 the title has been closely associated with the Royal family (see also Duke of Cambridge, Marquess of Cambridge).
The first Earl of the fourth creation, the Marquess of Hamilton, was at the time sixth in line to the Crown of Scotland (after the Duke of Rothesay, later King Charles I, his sister Elizabeth and her children); his grandfather Lord Arran had been heir-presumptive to, and Regent for, Mary, Queen of Scots.
The Duke of Hamilton currently holds the title Earl of Arran and Cambridge in the Peerage of Scotland, which is not related to this earldom. From 1664, the title Duke of Cambridge superseded that of the Earl of Cambridge.