Arnulf III (died 22 February 1071) was Count of Flanders from 1070 until his death at the Battle of Cassel in 1071.
Born c. 1055, Arnulf was the eldest son of Count Baldwin VI of Flanders and Countess Richilde of Hainaut.
[5] Robert refused and continued his aggression against Richilde and Arnulf, at which point Philip amassed an army which he brought to Flanders.
[4] The French army was accompanied by Norman troops, probably sent by Baldwin and Robert's sister Queen Matilda and led by William FitzOsborn.
[5] Among the dead was Arnulf, killed by Gerbod the Fleming, 1st Earl of Chester, possibly by accident.