Mathematician:William Rowan Hamilton

Irish mathematician and physicist famous (among other things) for:
 * Creating the field of Hamiltonian mechanics;
 * The discovery of quaternions;
 * Development of aspects of graph theory.

Nationality
Irish, although at that time Ireland was politically part of Great Britain.

History

 * Born: 4 August 1805
 * Died: 2 September 1865

Theorems and Definitions

 * Hamiltonian Mechanics
 * Hamiltonian Graph
 * Hamiltonian Path
 * Hamilton Cycle
 * Hamiltonian Group
 * Hamiltonian Matrix
 * Quaternions
 * Hamilton's Equations

Books and Other Publications

 * 1826: Theory of Systems of Rays
 * 1834: On a General Method in Dynamics
 * 1835: Algebra as the Science of Pure Time
 * 16 October 1843: $$i^2 = j^2 = k^2 = i j k = -1$$ (in the stone of Broome Bridge)
 * 1853: Lectures on Quaternions
 * Elements of Quaternions (posthumous)