The district of County Donegal that borders the western bank of the River Foyle is traditionally known as the Laggan.

[3] This district includes the villages of St Johnston and Carrigans, both of which are nestled on the banks of the River.

Claudius Ptolemy's Geography (2nd century AD) described a river mouth called Ουιδουα (Widua, from PIE *widhu, 'tree') which referred to the Foyle.

However, this proved unnecessary as the main port was moved several miles north of the city and the large vessels it was designed for never had to come so far south.

Due to the presence of three bridges over the river in Derry, some people choose to attempt suicide by jumping into the deep and fast-moving Foyle.

[8][9] Prior to the Plantation of Ulster the fishing rights on the River would have been owned by the O’Neills and the O’Donnells, the Chieftains of Tír Eoghain and Donegal respectively.

The case was heard by Mr Justice George Gavan Duffy in the high court in Dublin during 1947–48.

Both Governments agreed to buy the fishing rights for the sum of £110,280 on condition that they drop the appeal.

[13] The village of St Johnston, which lies on the County Donegal bank of the river, is a major fishing settlement on the Foyle.