Ireland

James Shields, US army general, the only person to be elected a senator by 3 states, is born in Altmore, Co. Tyrone

John Jones, sculptor, is born in Dublin

William Dool Killen, ecclesiastical historian, is born in Ballymena, Co. Antrim

Daniel Maclise, painter, born in Co. Cork

Daniel Maclise RA (25 January 1806 – 25 April 1870) was an Irish history painter, literary and portrait painter, and illustrator, who worked for most of his life in London, England.

The Irish dead at the Battle of Trafalgar include Lieutenant William Ram, son of Abel Ram, MP for Co. Wexford, who is killed on board the Victory

Birth in Dublin of Sir William Rowan Hamilton, mathematician and astronomer

Sir William Rowan Hamilton (August 04, 1805 - September 02, 1865) was an Irish mathematician, physicist, and astronomer. Hamiltons discovery of quaternions is his best known investigation. Hamilton also contributed to the development of optics, dynamics, and algebra. Hamiltons research was later significant for the development of quantum mechanics. Dr. John Brinkley, bishop of Cloyne, is said to have remarked in 1823 of Hamilton at the age of eighteen: This young man, I do not say will be, but is, the first mathematician of his age. He made important contributions to optics and to dynamics. Hamiltons papers on optics and dynamics demonstrated theoretical dynamics being treated as a branch of pure mathematics.

Brian Merriman , died

Brian Merriman or in Irish Brian Mac Giolla Meidhre (c. 1747 – 27 July 1805) was an Irish language bard, farmer, and hedge school teacher from rural County Clare.

Michael Doheny, poet and Young Irelander, is born near Fethard, Co. Tipperary

James Henthorn Todd, scholar, is born in Dublin

James Henthorn Todd (23 April 1805 – 28 June 1869) was a biblical scholar, educator, and Irish historian. He is noted for his efforts to place religious disagreements on a rational historical footing, for his advocacy of a liberal form of Protestantism, and for his endeavors as an educator, librarian, and scholar in Irish history.

Sir William Rowan Hamilton, mathematician and astronomer, is born in Dublin

Sir William Rowan Hamilton MRIA, FRAS (3/4 August 1805 – 2 September 1865) was an Irish mathematician, astronomer, and physicist. He was the Andrews Professor of Astronomy at Trinity College Dublin, and Royal Astronomer of Ireland, living at Dunsink Observatory.