Born in Pershore, Worcestershire, Leader was the eldest son of Benjamin Williams LEADER RA (1831-1923) of Burrows Hall, Gomshall, Surrey, and his wife, the Plymouth-born flower artist Mary Eastlake (1853-1938). He attended Charterhouse school and was admitted as a pensioner at Trinity, Cambridge on June 30, 1896. He studied art at Bushey and at Newlyn. Iris Green identifies him as a pupil of Stanhope FORBES and as attending the FORBES SCHOOL, but no date is specified.The records show that he sold his first painting, Surrey Pines, at NAG in 1904.

In 1910 he was married to Isabella Anderson. In Lamorna, the Leaders lived at Oakhill (1911-13), The Reens (1913-14) and then built the house called Rosemerrin in the style of a Cornish manor in 1914-15.

When he and Belle moved on to their new home at Rosemerrin, their cottage at Oakhill was occupied by the Knights. Sadly he had little time to enjoy the house and beautiful garden which he and Belle created together. He was a Captain in The Queen's Royal West Surrey Regiment and Duke of Wellington's West Riding Regiment. Leader was killed in action on Oct 12, 1916 on active service in France at the age of thirty-nine.

Ella Louise NAPER designed his memorial plaque that hangs today in St Buryan Church (see Branfield, Ill, p46). He is also commemorated at Thiepval Memorial, Somme, France.

His wife Isabella (Belle) also painted but seldom exhibited.