This plaque marks the site of the childhood home of William Rowan Hamilton, at 36 Dominick Street, Dublin 1 (now 21-24 Bolton Square).

Sir William Rowan Hamilton (1805–1865) was an Irish mathematician and physicist renowned for his contributions to algebra, optics, and mechanics. A child prodigy in languages, he later focused on mathematics and made significant discoveries, including the reformulation of Newtonian mechanics, known as Hamiltonian mechanics.

He also invented quaternions, an extension of complex numbers, which laid the groundwork for modern vector analysis. In honour of his invention 16 October is celebrated as Hamilton Day, marking the day he ‘discovered’ quaternions and carved the formula into the bridge over the Royal Canal, at Cabra.

Hamilton served as the Royal Astronomer of Ireland and Professor of Astronomy at Trinity College Dublin, based at Dunsink Observatory, where he lived and conducted much of his work.

Hamilton’s work greatly influenced the development of modern physics and mathematics.

The plaque was unveiled on 16 October 2024.