Thomas Sinclair (politician, 1838–1914)

Sinclair's father went into business with his brother John (1808–1856), setting up a provisions and general merchant store at 5–11, Tomb Street, Belfast.

[1][3] Despite numerous requests, Sinclair never stood for parliament, instead he served as Deputy lieutenant, Justice of the peace, president of the Ulster chamber of commerce in 1876 and 1902, and privy councillor in 1896.

9 months after the convention, Sinclair was appointed to the executive committee of the new unionist clubs, which were founded to protect the union.

He supported Plunkett's backing of T. P. Gill as secretary of the Irish Agricultural Organisation Society in 1899, in the face of strong protest by conservative unionists.

Through his work with the recess committee, he ensured that the new Department of Agriculture's vocational and technical education would remain secular.

This resulted in the clubs taking up arms, with over 80 groups drilling by April 1911, which would go on to form the core of the Ulster Volunteers.

On 25 September 1911, Sinclair was appointed to a five-man commission tasked with writing a constitution for a provisional government of Ulster.

Later in 1912, he was tasked with drafting Ulster's Solemn League and Covenant, a pledge for signatories to oppose and defeat home rule and never recognise an Irish parliament.