Simon (Baron) de MONTAGU
Simon (Baron) de was born about 1250 in Montacute Somersetshire, England.  He died on September 26th, 1316.

 Hawaise de ST.  AMAND
Hawaise de was born about 1252 in Isle of Man.  She died in 1287.

 William de MONTAGU
William de was born about 1275 in Cassington, Oxforshire, England.  He died in Windsor Castle, Windsor, Berkshire, England.