Dr Baker, whose father was a butler, attended a number of small schools in Cambridge before gaining a scholarship to The Perse, where he excelled in Mathematics and Classical Greek.  He was elected a Fellow of St John’s College in 1889 and in the same year won the Smith’s prize. Dr Baker would remain at Cambridge for the whole of his career, strongly influencing the teaching of pure mathematics in the university and in the rest of Great Britain.

From 1914 until he retired in 1936 he was Lowndean Professor of Astronomy and Geometry. He justified the ‘astronomy’ title in his chair by lecturing on periodic orbits and other astronomical topics, but he continued to undertake research exclusively in pure mathematics.

Inspired by Felix Klein to study algebraic function theory, he wrote the important Abel’s Theorem and the Allied Theory of Theta Functions in 1897 and another major contribution, Multiply Periodic Functions, in 1907. From 1911 he studied birational geometry, publishing his most important contribution, a six-volume masterpiece, Principles of Geometry, from 1922 to 1925. In 1943 Dr Baker published An Introduction to Plane Geometry.

He was elected to a Fellowship of the Royal Society in 1898, was secretary of the Cambridge Philosophical Society in 1897 and won the De Morgan Medal of the London Mathematical Society in 1905.