 At their head, FitzWalter waged an armed campaign against the neighbouring town of Colchester, almost from the moment he reached adulthood.The townsmen seem to have exacerbated the dispute by illegally entering FitzWalter's park in Lexden; in return, FitzWalter banned them from one of their own watermills and then, in 1342, he besieged the town, preventing anyone entering or leaving for some weeks, as well as ransacking much property and destroying the market.One historian has described him, in his activities, as the medieval equivalent of a 20th-century American racketeer.