The Exeter Ship Canal, also known as the Exeter Canal is a canal leading from (and beside) the River Exe to Exeter Quay in the city of Exeter, Devon, England. It was first constructed in the 1560s predating the "canal mania" period and is one of the oldest artificial waterways in the UK. History At the start of Exeter's history, the River Exe was tidal and navigable up to the city walls enabling it to be a busy port. In the 1270s or 1280s, the Countess of Devon, Isabella de Fortibus, built a weir across the river to power her mills (this weir is remembered in the name of the nearby suburb Countess Wear). This had the effect of cutting off Exeter's port from the sea and damaging its salmon fisheries. In 1290, trade with Exeter's port was restored, only to be blocked by a new weir built in 1317 by Hugh de Courtenay, 9th Earl of Devon (Isabella's cousin), who also built a quay at Topsham. Because of the blockages on the river, boats were forced to unload at Topsham and the earls were able to exact large tolls to transport goods to Exeter. For the next 250 years the city petitioned the King to have the waterway reopened, to no avail, until 1550 when Edward VI finally granted permission. However, it was by then too late because the river channel had silted up. In 1563, Exeter traders employed John Trew of Glamorgan to build a canal to bypass the weirs and rejoin the River Exe in the centre of the city where a quay would be built. Work began in February 1564, and was completed in Autumn 1566 or early 1567. The canal had three locks with vertical gates – the first pound locks to be built in Britain. They accommodated boats up to 16 tonnes. The original cut was deep and wide (0.9 m by 5 m). It ran one and from just below the Countess Weir to the centre of Exeter. This navigation was not very effective; it could not be entered at all states of the tide, and the double transfer of cargo over such a short distance made it uncompetitive with road transport. The weir that maintains the water level in the quay is still named "Trew's Weir" after the canal's builder. In 1677 the canal was extended and the entrance was moved downstream