One line of argument stemmed from the 1259 treaty agreed by Edward's grandfather, Henry III, under which Henry had agreed to give homage for Gascony; Edward's lawyers observed that this treaty, which underpinned Edward's 1303 treaty with France, had been a bilateral agreement between the two kings, rather than a conventional feudal agreement.
Unha liña argumental xurdiu do tratado de 1259 acordado polo avó de Eduardo, Henrique III, segundo o cal este último aceptara render homenaxe por Gascuña; os avogados de Eduardo observaron que este tratado, que sustentaba o tratado de Eduardo de 1303 con Francia, fora un acordo bilateral entre ambos os reis en lugar dun acordo feudal convencional.