Joan of Lancaster (c. 1312 – 7 July 1345) sometimes called Joan Plantagenet after her dynasty's name, was the third daughter of Henry, 3rd Earl of Lancaster and Maud Chaworth.
She married John de Mowbray, 3rd Baron Mowbray on 28 February 1326 or 1327. They had three children:
Blanche de Mowbray (died 1409), married firstly John Segrave, secondly Robert Bertram, thirdly Thomas Poynings, fourthly Sir John Worth, and fifthly Sir John Wiltshire.
Eleanor de Mowbray, married firstly Roger La Warre, Lord La Warre and secondly Sir Lewis de Clifford.
John de Mowbray, 4th Baron Mowbray (25 June 1340-1368), married Elizabeth de Segrave
She died in Yorkshire, England of plague. Her husband would remarry Elizabeth de Vere, widow of Sir Hugh de Courtenay and daughter of John de Vere Earl of Oxford and his wife Maud de Badlesmere.