[1] The constituency returned one Member of Parliament (MP) to the House of Commons of the United Kingdom, elected by the first past the post voting system.
The sitting Unionist MP, the James Hamilton succeeded his father on his death as the Duke of Abercorn, so vacated his seat in the House of Commons to take up his seat in the House of Lords.
The Catholic clergy, whose authority on the choice of nationalist candidate was total, surprisingly selected Liberal David Hogg, a 73-year-old local shirt manufacturer and a Protestant.
[2] The date of poll was set at 30 January, just 27 days after the death of the old Duke.
Hogg died in August 1914 causing another by-election at which the Liberal, Sir James Brown Dougherty was returned unopposed.