The Earl of Leicester is an extinct title in the Peerage of England, and is a title in the Peerage of the United Kingdom, created in 1837.
The title was originally held by the Beaumonts. After the death of Robert, the fourth Beaumont Earl, the title was inherited by his nephew, Simon de Montfort, but King John confirmed the inheritance only in 1207. Then, the title passed to the famous Simon de Montfort, who was killed in battle in 1265, when the title was attained by the King.
The title was created once again for Edmund, the son of King Henry III. His descendant, Henry of Grosmont was created Duke of Lancaster in 1361, but the dukedom became extinct, while the earldom passed to William V, Count of Holland, husband of the Duke's daughter Matilda. (Modern rules allow inheritance only by descendants, but the previous rules for inheritance allowed inheritance by sons-in-law in the absence of male heirs.) Then, the title passed to the John of Gaunt, husband of the Duke's other daughter, Blanche. John of Gaunt was later Duke of Lancaster. Both the dukedom and the earldom were inherited by John of Gaunt's grandson, Henry Bolingbroke, and both titles ceased to exist when Henry usurped the throne, as the titles "merged into the crown." (The Sovereign is supposed to be above all peers, while holding a title of peerage would connote equality with the peers. Therefore, the Sovereign cannot hold a title of peerage.)
Thereafter, the title was again created for Queen Elizabeth I's favourite, Robert Dudley. Since Dudley died without heirs, the title became extinct at his death. The title was again created for Robert Sidney, his nephew. The Sidneys retained the title until the death of the seventh Earl, when the title again became extinct. The title was then given to Thomas Coke, but it became extinct when he, too, died without heirs.
The title was again bestowed upon George Townshend, later the first Marquess Townshend. The earldom became extinct yet again upon the death of the third Marquess in 1855. Prior to the extinction of the earldom, however, another individual, also named Thomas Coke, was granted the earldom of Leicester. Technically, Coke became the Earl of Leicester of Holkham, and the Marquess Townshend remained the Earl of Leicester. However, the Earls of Leicester of Holkham are usually counted among the Earls of Leicester, and as the term "of Holkham" is not needed to make differentiatiations, it is not often used when speaking of the title.
Earls of Leicester, first Creation (1103)
Earls of Leicester, second Creation (1265)
Dukes of Lancaster, first Creation (1351)
Earls of Leicester, second Creation
Dukes of Lancaster, second Creation (1362)
Earls of Leicester, third Creation (1564)
Earls of Leicester, fourth Creation (1618)
Earls of Leicester, fifth Creation (1744)
Earls of Leicester, sixth Creation (1784)
Marquesses Townshend (1787)
Earls of Leicester, seventh Creation (1837)