Earl of Lancaster

Earldom of Lancaster
Arms of Edmund Crouchback, 1st Earl of Lancaster, 1st Earl of Leicester: Royal arms of King Henry III with a label of three points of France for difference
Creation date	30 June 1267 (1267-06-30)
Created by	Henry III of England
Peerage	Peerage of England
First holder	Edmund Crouchback
Last holder	Henry of Grosmont
Subsidiary titles	Earl of Leicester
Extinction date	23 March 1361 (1361-03-23)
Seat(s)	Lancaster Castle

The title of Earl of Lancaster was created in the Peerage of England in 1267. It was succeeded by the title Duke of Lancaster in 1351, which expired in 1361. (The most recent creation of the ducal title merged with the Crown in 1413.)

King Henry III of England created the Earldom of Lancaster—from which the royal house of Henry IV was named—for his second son, Edmund Crouchback, in 1267. Edmund had already been created Earl of Leicester in 1265 and following the Second Barons' War and the death and attainder of the king's rebellious brother-in-law Simon de Montfort, 6th Earl of Leicester^[1] in 1265, the latter's lands, including most notably Kenilworth Castle in Warwickshire, had been awarded to him.

When Edmund's son Thomas, 2nd Earl of Lancaster, inherited the estates and title of his father-in-law Henry de Lacy, 3rd Earl of Lincoln, he became at a stroke the most powerful nobleman in England, with lands throughout the kingdom and the ability to raise vast private armies to wield power at national and local levels.^[2] This brought him—and his younger brother Henry, 3rd Earl of Lancaster—into conflict with their first cousin King Edward II, leading to Thomas's execution. Henry inherited Thomas's titles and he and his son Henry of Grosmont, 1st Duke of Lancaster, gave loyal service to Edward's son— King Edward III.