Geoffroi Wallis ( -1471), was Seigneur of St Germain. A contract of 1565 in De La Croix' Jersey calls his grandfather Valls. In Jurat lists his father appears as Walich. A letter from the Bailiff refers to Geoffroi as Wallisch. The Royal Court called him Walysse, Walsche, Walich, and Walsh. His cousins, when claiming his estate spelt their name Walsh. The Inquest of 1532 used the form Wallys.
His grandfather, Geoffrey Wallis, a Dorset man of good family, settled in the island, when he married a Jersey heiress, Eleanore de Chesney, widow of the Seigneur of Handois. He had a son, Raulin, who became a Jurat. Raulin's son, Geoffroi, inherited through his grandmother the fiefs of Handois in St Lawrence, Paisnel in St John, Morville in St Ouen, and Grainville in St Saviour. These four fiefs now began to be considered as one, and were called the Fief of St Germain from the house, Les Saints Germains, at St. Lawrence in which the family lived.
It was one of the largest fiefs in the island, containing 210 vergees. Geoffroi married Katherine, only child of Jean De Vinchelez, who inherited the Vinchelez estates. He was a soldier, and in the Wars of the Roses followed the banner of Warwick the Kingmaker, being one of the private army which the Earl maintained, who all wore the badge of the ragged staff, and according to Holinshed ate six oxen daily for breakfast.
In 1457 Warwick, as Lord of the Isles, made him Captain of Castle Cornet, Guernsey. In 1464 he was appointed Surveyor of the Scrunity in the Port of Poole. The Chronicler says that he accompanied Warwick on his embassy to Spain but, as Warwick never went to Spain, this probably means the embassy to France in 1467, which caused the breach between Warwick and Edward IV.
In 1468 Wallis was back in Guernsey as Lieut-Governor. In 1470 he followed the King-maker from the Yorkist to the Lancastrian side, collected his Jersey tenants, and joined the force which landed with Warwick at Dartmouth in September and restored Henry VI to the throne.
In March 1471 Edward IV landed again in Yorkshire. On Easter Day, April 14, the armies met at Barnet. Warwick made his mounted men send their horses to the rear to show there would be no retreat. When they were outflanked and defeated, their heavy armour made escape impossible. Wallis fell with his leader. Some of his more lightly armed billmen made their way to Southampton.
At an Inquest on the Estate later, Jean Mourant testified that he had been present at Southampton, “when divers of Geoffroi's men were captured in that town by officers of the King and hanged for treason". Others more fortunate escaped home to Jersey.
Wallis' estates were confiscated. He had no children. His widow, who survived him for 50 years, married Philippe de La Hougue. At the accession of Henry VII some cousins claimed the estate, pleading that a Lancastrian King should not maintain a sentence of treason passed by Yorkists on a man who died fighting for the House of Lancaster. The litigation dragged on until 1532, but the Crown retained most of the property.