 The sheltered waters of Blakeney Haven had brought prosperity to the internationally important Glaven ports of Cley, Wiveton and Blakeney. Blakeney gained its market charter in 1222, and the three ports, along with Salthouse, were jointly required to provide three ships for Edward II in 1322, having previously contributed to his father's navy in 1301. By the early 15th century, Blakeney was one of the few ports permitted to trade in horses, gold and silver, through "merchants sworn by oath to the king", which contributed to the town's growing wealth. In 1640, land reclamation schemes, especially those by Henry Calthorpe just to the west of Cley, led to the silting up of the shipping channel and relocation of the wharf, and further reclamation east of the Glaven meant that all the Glaven ports declined; Cley and Wiveton silted up in the 17th century, but Blakeney had packet ships until 1840. Similar marsh reclamation schemes took place elsewhere, often with the same consequence for the local harbours, as for example at Holkham. Only Wells-next-the-Sea had significant trade into the late 20th century.
