At an early age, William was sent to William de Tancarville to learn the skills of knighthood. He was knighted in 1166. He then crossed the channel to Normandy and went to serve under his uncle, Patrick, the Earl of Salisbury. He fought in Ponthieu in 1168 when greatly outnumbered, his uncle was killed and William was taken prisoner. Marshal's great skill and bravery was noticed and he was ransomed by Queen Eleanor of England. 