He served in Wales, Flanders, and Scotland, where he was present at the Battles of Falkirk, Galloway & Stirling, and at the siege of Caerlaverock.
He died in 1327.
Edmund appears in the following rolls, The Falkirk Roll, H47; The Caerlaverock Poem, K86; The Galloway Roll, GA256 & The Stirling Roll, ST79, where he bears
Azure billetty a fess indented or
John Deincourt, in The Caerlaverock Poem, K104; Glover's Roll, B107 & St George's Roll, E167, and Ralph Deincourt, in St George's Roll, E267, both bear the same arms.
William Deincourt, in The Caerlaverock Poem, K86, bears the arms with a label. A person of the same same name, who fought at the Battle of Bannockburn in 1314, also bears the arms with a label.
Azure billetty a fess indented or a label gules
John Deincourt, in The Galloway Roll, GA258, and William Deincourt, in The Stirling Roll, ST80, bear the arms with different tinctures.
Argent billetty and a fess dancetty sable
At this period the difference between the fess indented and dancetty was not significant.