Jean de Gisors
Jean de Gisors (1133 - 1220) was a Norman lord of the fortress of Gisors in Normandy, where meetings were traditionally convened between English and French kings and where, in 1188, a curious squabble occurred that involved the cutting of an elm. Until 1193 he was a vassal of the king of England - Henry II, and then Richard I. He owned property in England, in Sussex, and the manor of Titchfield in Hampshire.
Between 1170 and 1180 he purchased the manor of Buckland, Hampshire from the de Porte family. He is acknowledged as the founder of what was to become the city of Portsmouth in southern England, and it was his authority and ambition that drove the construction of the early town. Old Portsmouth is clearly a planned town and much of what has survived was probably designed by him using the standard medieval grid pattern, which can also be seen in towns such as Salisbury.
One of the first constructions ordered by de Gisors was the Chapel of St. Thomas, which he had dedicated to St Thomas à Becket who had spent much of his life in Gisors. De Gisors gave land in Portsmouth to the Augustinian canons of Southwick Priory so that they could build a chapel "to the glorious honour of the martyr Thomas of Canterbury, one time Archbishop, on (my) land which is called Sudewede, the island of Portsea". This foundation became Portsmouth Cathedral.
However the patronage of de Gisors was not to last, as after his support for an unsuccessful rebellion in Normandy he paid the price by forfeiting all his lands, including Portsmouth, to Richard I.
He has been claimed to be the second grand master (1188-1220) of the supposed Priory of Sion.