Margaret De Mowbrays

Margaret de Mowbray was the elder daughter of Thomas de Mowbray by his wife,
Elizabeth, daughter and co-heir of Richard FitzAllen, Earl of Arundel and
cousin and co-heir of John Mowbray, Duke of Norfolk. Thomas de Mowbray was a
son and heir of Lord John Mowbray by Elizabeth Segrave (a direct descendant of
Robert de Vere, who signed Magna Carta as surety for King John). John de
Mowbray was directly descended from Henry de Bohun, Roger Bigod, Hugh
Bigod,William de Mowbray,Gibbertde Clare,Richard de Clare,John de Lacies,Saber
de Quincey and William de Albina each of whom signed Magna Carta as surety for
King John. Lord de Mowbray, was a Crusader and fell in Battle in 1368.
Margaret de Mowbray married Sir Robert Howard. With this marriage to Lady
Margaret Mowbray, begins the great record of the Howards, for through her, they
heired titles and estates innumerable.

Source: Notable Southern Families, see Howard Family by Burke, pages 100-119.