He was summoned to the Parliament of Simon de Montfort in 1265, but such summonses have later been declared void.
However, in 1283 he was summoned to Parliament by King Edward I as Lord Mowbray.
[2] Mowbray married Rose, a daughter of Richard de Clare, 6th Earl of Gloucester.
They had at least two children: Roger de Mowbray was buried in Fountains Abbey.
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