1. Sir William Rowan Hamilton was born in Dublin in 1805, and at the age of five was already reading Latin, Greek and Hebrew. He entered Trinity College Dublin in 1823, and while still an undergraduate was, in 1827, appointed Andrewes Professor of Astronomy at that university, and Director of the Dunsink Observatory with the title “Royal Astronomer of Ireland.” In that same year he began to develop geometric optics on extremal principles and in 1834/35 extended these ideas to dynamics, with the introduction of the principle of least action, the Hamiltonian function, and his canonical equations of motion. He was knighted in 1835 and was President of the Royal Irish Academy from 1837 to 1845. His great discovery of quaternions was made in 1843. He died in 1865 at Dunsink.