15th Century
While the eleventh (by some counts) holder of the title, Isabel Douglas, Countess of Mar, was alone at the Kildrummy Castle, Alexander Stewart entered it and forced her to sign a charter on August 12, 1404 yielding the earldom to him and his heirs. She revoked the charter later that year, but on marrying him, she gave him the earldom for life with remainder to her heirs. The King confirmed her last action the next year.
In 1426, Stewart resigned the title so that he could be granted a new one by the King, the new title being more "legitimate". The King did so, but specified that the earldom and associated lands would revert to the Crown upon the death of the Earl. In 1435, the Earl died, and Robert, Lord Erskine claimed the title, but the King claimed its lands under the specifications of reversion made in the patent. The issue remained unresolved until 1457, when James II obtained a court order declaring the lands as crown possessions. Thereafter, he bestowed the title on his son John, who died without heirs in 1479. It was next granted to James' other son, Alexander, Duke of Albany, but the title was then declared forfeit because of Alexander's alliances with the English. James III created his son John Earl of Mar in 1486, upon whose death in 1503 the title became extinct again.
Read more about this topic: Earl Of Mar