 In 1345 Edward III was planning a major assault on France . A three @-@ pronged attack would have the Earl of Northampton attacking from Brittany , the king himself from Flanders , while Grosmont was dispatched to Aquitaine to prepare a campaign in the south . Moving rapidly through the country , he confronted the Comte d ’ Isle at Auberoche on 21 October and there achieved a victory described as " the greatest single achievement of Lancaster 's entire military career " . The ransom from the prisoners has been estimated at £ 50 @,@ 000 . The next year , while Edward was carrying out his Crécy campaign , Grosmont laid siege to , and captured , Poitiers , before returning home to England in 1347 . 
 In 1345 Edward III was planning a major assault on France . A three @-@ pronged attack would have the Earl of Northampton attacking from Brittany , the king himself from Flanders , while Grosmont was dispatched to Aquitaine to prepare a campaign in the south . Moving rapidly through the country , he confronted the Comte d ’ Isle at Auberoche on 21 October and <a href='dey_it' title='1'><mark>there</mark></a> achieved a victory described as " the greatest single achievement of Lancaster <a href='null_genetive' title='2'><mark>'s</mark></a>entire military career " . The ransom from the prisoners <a href='been_done' title='3'><mark>has</mark></a> been estimated at £ 50 @,@ 000 . The next year , while Edward was carrying out his Crécy campaign , Grosmont<a href='been_done' title='4'><mark></mark></a> laid siege to , and captured , Poitiers , before returning home to England in 1347 . 
In 1345 Edward III was planning a major assault on France . A three @-@ pronged attack would have the Earl of Northampton attacking from Brittany , the king hisself from Flanders , while Grosmont was dispatched to Aquitaine to prepare a campaign in the south . movin rapidly thru the country , he confronted the Comte d ’ Isle at Auberoche on 21 October and it achieved a victory described as " the realest single achievement of Lancaster  entire military career " . da ransom from the prisoners done been estimated at £ 50 @,@ 000 . The next year , while Edward was carrying outt his Crécy campaign , Grosmont done laid siege to , and captured , Poitiers , b4 returning home to England in 1347 .