(THOMAS DE LEYBURN, son and heir apparent. In 1303, going to Scotland in his father's company, he had respite of the aid in Kent. In 1305, as Thomas de Leyburn, knight, he attested a charter at Doncaster. From February to March 1306/7 he was serving in Scotland by the King's command in a raid upon Bruce.
He married Alice, daughter of Ralph DE TONY, TONI or TOSNY, of Castle Maud, co. Radnor, &c., and in 1309 heir to her brother, Robert DETONY (or TANY), LORD TOSNY. On their marriage William the father settled his castle of Leybourne on them and their issue. He died v.p. and s.p.m., before 30 May 1307. In 1308 his widow made a fine in 100s. to have the manor of Leybourne. She married, 2ndly, in or before May 1310, Guy (DE BEAUCHAMP), EARL OF WARWICK, who died in 1315. She married, 3rdly, William LA ZOUCHE, of Mortimer, LORD ZOUCHE. She was living in November 1374, but died before 15 February 1324/5.] [Complete Peerage VII:638, (transcribed by Dave Utzinger)]