Thomas Sinclair, Ulster Scots businessman and politician who drafted the Ulster Covenant, is born in Belfast on September 23, 1838.

Sinclair’s parents are Thomas (1811–1867), merchant and ship-owner, and Sarah Sinclair (née Archer) (1800–1849). His father goes into business with his brother John (1808–1856), setting up a provisions and general merchant store at 5–11 Tomb Street, Belfast. John marries Eliza Pirrie, a relative of the prominent ship builder William Pirrie, 1st Viscount Pirrie. After the death of his father in 1867, Sinclair inherits £35,000 as his mother, brother and sister are all deceased.

In 1876, Sinclair marries Mary Duffin of Strandtown Lodge, Belfast. They have a daughter, Frances Elizabeth Crichton, and a son. She dies in 1879. He marries Elizabeth Richardson in 1882. She is the niece of John Grubb Richardson and the widow of Sinclair’s cousin, John M. Sinclair. They have three sons and two daughters.

Sinclair attends Royal Belfast Academical Institution and Queen’s College Belfast, graduating with a BA with gold medal for mathematics in 1856, and an MA with gold medals in logic, political economy, and English literature in 1859. After his father’s death, he takes over running the family business. He expands and grows it by merging it with another large provisions business with American branches, Kingan & Co. He is related to the Kingans through his cousin Sarah, who is married to the owner, Samuel Kingan.

Despite numerous requests, Sinclair never stands for parliament, instead serving as deputy lieutenant, justice of the peace, president of the Ulster chamber of commerce in 1876 and 1902, and privy councilor in 1896. Having been a supporter of William Ewart Gladstone, he joins the Ulster Liberal Party in 1868, supporting the land acts of 1870 and 1881. Following the home rule bill of 1886, he convenes a meeting in the Ulster Hall of liberals on April 30, 1886, which passes a resolution in condemnation of the bill. Forming the Ulster Liberal Unionist Association, of which he is chair, he organises the Ulster Convention in Belfast. Held on June 17, 1892, it sees 11,879 Ulster unionists meet to protest home rule. Nine months after the convention, he is appointed to the executive committee of the new unionist clubs, which are founded to protect the union. The defeat of the British Liberal Party in 1895 significantly decreases the threat of home rule, leading to the unionists’ clubs being suspended, and Sinclair returning to his activities in liberal reform. He is the leading Ulster member of the recess committee from 1895, which is founded by Horace Plunkett. He supports Plunkett’s backing of T. P. Gill as secretary of the Irish Agricultural Organisation Society (IAOS) in 1899, in the face of strong protest by conservative unionists.

Despite his unionist politics, Sinclair is nonsectarian, and during his time as chairman of the convocation of the Queen’s University he defends the core non-sectarian principles of the institution and refuses to allow any form of denominational teaching. Through his work with the recess committee, he ensures that the new Department of Agriculture’s vocational and technical education will remain secular.

By 1904 and the devolution crisis, Sinclair sides with conservative unionists, being of the 30 members of the standing committee of the Ulster Unionist Council on its foundation in December 1904. He proposes that all suspended unionist clubs be reestablished in January 1911, with the purpose of increasing their membership and responsibilities. This results in the clubs taking up arms, with over 80 groups drilling by April 1911, which goes on to form the core of the Ulster Volunteers. On September 25, 1911, he is appointed to a five-man commission tasked with writing a constitution for a provisional government of Ulster. He is one of the contributors to the 1912 collection of essays from the unionist party, Against home rule. He identifies the six county Ulster, proffering the idea of a two-nation island, warning that Ulster will never form part of an independent Ireland. Later in 1912, he is 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.

Sinclair dies from kidney failure on February 14, 1914, at his home, Hopefield House, Belfast. His funeral procession on February 18 is headed by 200 UVF officers. The Ulster Museum holds a portrait of Sinclair by Frank McKelvey, and QUB holds one by Henrietta Rae (pictured above). A memorial window at Church House, the headquarters of the Presbyterian Church, is unveiled in his memory on June 8, 1915, and there is a Sinclair Memorial Hall opened in his honour on September 10, 1915. A blue plaque is erected to him on the Duncairn Centre for Arts & Culture.

The Sinclair Ward in the Royal Victoria Hospital, Belfast, is originally funded by Sinclair’s father, in honour of his wife Sarah under the Sinclair Memorial Fund. The surgeon and politician Thomas Sinclair is also a relative.