Ralph Tesson de la Roche-Tesson, III

"Tyson or Tisson, a baronial name.The Tessons were commonly said to have possessed a third of Normandy. The name of this family was originally Ticio, and it is stated to have been seated in the vicinity of Angouleme (whence its Gothic origins may be inferred), and to have been distinguished in war against the Saracens, c 725 (Des Bois, Art. Achard).The Tessons were afterwards seated in Anjou (Vaultrier, Apud Mem. Soc. Ant. Norm. x 78).

Radulphus Taxo, of Angers, in 1028 witnessed a charter regarding the Abbey of Coulombs (Gall. Christ. viii.297. Instr.). 'Ralph T. led 120 knights of his barony to the aid of Duke William at the Battle of Val des Dunes, 1047, and was created Viscount of the Cotentin. He founded the Abbey of Fontenay, near Caen, and from him descended the powerful family of Tesson in Normandy. Gilbert Tyson or Tesson, his brother, obtained the barony of Alnwick from Edward the Confessor, and fell at the Battle of Hastings. William, his son, had a daughter who married Ivode Vesci. Gilbert Tyson, another son, held great estates in York, Lincoln and Notts 1086 (Domesd.). Adam Tyson granted lands in Notts to the Hospitallers, t. Rich I (Mon. ii) and to Thurgarten Priory (Ib.93). In the 13th century Warin Fitzgerold held lands late the fee of Ralph Tesun (Testa 77). This family appears also to have been the origin of those of PERCY, MARMION and BYRON."

excerpted from The Norman people and their existing descendants in the British dominions and the United States of America (author unknown), Henry S. King & Co, 1874, p. 427. Reprinted online (Google Books and archives.com).