Cornelius Vermuyden (1595-11 October 1677) was a Dutch engineer who introduced land reclamation to England. He repaired the Dagenham sea wall and helped in draining the Hatfield Chase for Dutch and English capitalists, and the local fenmen hunters and fishers attacked the Dutch workers due to their loss of their livelihood; the fenmen were later compensated. Vermuyden's techniques were putting in washes to catch floodwater in bad wealther (during the 1650s) and draining the eastern edge of the fen. In 1633, he became an English citizen.