The title Baron Mohun was created once in the Peerage of England

Peerage of England

The Peerage of England comprises all peerages created in the Kingdom of England before the Act of Union in 1707. In that year, the Peerages of England and Scotland were replaced by one Peerage of Great Britain....

. On 6 February 1299 John de Mohun was summoned to parliament. On the death of the second baron, the barony fell into abeyance. In 1431, Richard le Strange, 7th Baron Strange (second creation) became sole heir of the barony of Mohun, when both title merged and became abeyant on the death of Ferdinando Stanley, 5th Earl of Derby

Ferdinando Stanley, 5th Earl of Derby

Ferdinando Stanley, 5th Earl of Derby was the son of Henry Stanley, 4th Earl of Derby and Lady Margaret Clifford. According to the will of Henry VIII, his mother was heiress presumptive of Elizabeth I of England from 1578 to her own death in 1596...

 in 1594.

Barons Mohun (1299)

• John de Mohun, 1st Baron Mohun (d. 1330)
• John de Mohun, 2nd Baron Mohun
  John de Mohun, 2nd Baron Mohun
  John de Mohun, 2nd Baron Mohun, 9th Baron de Mohun of Dunster, KG was a founder member and the 11th Knight of the Most Noble Order of the Garter in 1348....
  
   (c.1320–1375) abeyant 1375
• Richard le Strange, 3rd Baron Mohun (1381–1449) sole heir 1431
• for further barons look at Baron Strange
  Baron Strange
  Baron Strange is a title that has been created several times in the Peerage of England. Two creations, one in 1295 and another in 1325, had only one holder each, upon the death of whom they became extinct. Two of the creations are still extant, however...
  
  (second creation) until 1594.