John Marmion

John de Grey, called John Marmion, was the elder son of John de Grey, first Baron Grey of Rotherfield, by Avice Marmion, through whom the Marmion estates at West Tanfield had come to the Greys.

Knighted, he married Elizabeth, a daughter and co-heiress of Sir Herbert St Quintin. A retainer of John of Gaunt, he sailed with the duke's 1386 campaign to press his claim to Castile and died in Spain in 1387, leaving no children.

His niece Elizabeth, daughter of his brother Robert, inherited the Marmion lands; his widow lies with him beneath the alabaster effigies in West Tanfield church.