Devenish Island is to be found in Lower Lough Erne north of Enniskillen, Co. Fermanagh. Aligned roughly north-south, it is about 2 km long and 1 km wide.
Devenish (daimh-inis, ox island) is an L-shaped island of 70 acres at the southern end of Lower Lough Erne, 1.5 miles downstream from Enniskillen.
Ballycassidy is approximately 2 miles north of DevenishIsland on the eastern shore of the lake.
In the cemetery on DevenishIsland closest to the shore, there are gravestones with the names of Cassidy physicians and priests dating back to the early 1700's.
DEVENISH, a parish, in the barony of MAGHERABOY, county of FERMANAGH, and province of ULSTER, 2 1/2 miles (N. W.) from Enniskillen; containing 8219 inhabitants.
The living is a rectory and vicarage, in the diocese of Clogher, constituting the corps of the prebend of Devenish in the cathedral of Clogher, and in the patronage of the Bishop: the tithes amount to £295.7.
The Island of Devenish appears to have derived its early importance from the foundation of a religious establishment, in honour of St.