Enniskillen (ˌɛnᵻsˈkɪlən , from Inis Ceithleann 'in'is'-'k'el'@N, 'Ceithlenn's island') is the largest town in County Fermanagh, Northern Ireland. It is in the middle of the county, between the Upper and Lower sections of Lough Erne. It had a population of 13,823 at the 2011 Census. Enniskillen Castle was built in the 15th century as a stronghold of the Maguires, before coming under English control in the early 17th century. The castle and town were expanded during the Plantation of Ulster. It was the seat of local government for the former Fermanagh District Council, and is the county town of Fermanagh.
The town's name comes from the Inis Ceithleann. This refers to Cethlenn, a figure in Irish mythology who may have been a goddess. Local legend has it that Cethlenn was wounded in battle by an arrow and attempted to swim across the River Erne, which surrounds the island, but she never reached the other side, so the island was named in reference to her. It has been anglicised many ways over the centuries – Iniskellen, Iniskellin, Iniskillin, Iniskillen, Inishkellen, Inishkellin, Inishkillin, Inishkillen and so on.
The town's oldest building is Enniskillen Castle, built by Hugh (Maguire) the Hospitable who died in 1428. An earthwork, the Skonce on the shore of Lough Erne, may be the remains of an earlier motte. The castle was the stronghold of the junior branch of the Maguires. The first watergate was built around 1580 by Cú Chonnacht Maguire, though subsequent lowering of the level of the lough has left it without water. The strategic position of the castle made its capture important for the English in 1593, to support their plans for the control of Ulster. The castle was besieged three times in 1594–95. The English, led by a Captain Dowdall, captured it in February 1594. Maguire then laid siege to it, and defeated a relieving force at the Battle of the Ford of the Biscuits at Drumane Bridge on the Arney River. Although the defenders were relieved, Maguire gained possession of the castle from 1595 to 1598 and it was not finally captured by the English until 1607.