John Collier was born January 27, 1850, the son of a judge and amateur artist, Lord Monkswell. He was educated at Eton and studied at the Slade under (Sir) E J Poynter, in Paris under Jean-Paul Laurens, and in Munich. Although not their pupil, he was encouraged and influenced by Sir Lawrence Alma-Tadema and Sir John Everett Millais.

Collier was from a talented and successful family. His grandfather, John Collier, was a Quaker merchant who became a Member of Parliament. His father (who was a Member of Parliament, Attorney General and, for many years, a full-time judge of the Privy Council) was created the first Lord Monkswell. He was also a member of the Royal Society of British Artists. John Collier's elder brother, the second Lord Monkswell, was Under Secretary of State for War and Chairman of the London County Council.

Collier's first wife, in 1879, was Marian Huxley, daughter of the biologist T. H. Huxley. She was also a painter, who studied, like her husband, at the Slade, and exhibited at the Royal Academy and elsewhere. After the birth of their only child, a daughter, she suffered severe post-natal depression and was taken to Paris for treatment where, however, she contracted pneumonia and died in 1887.

Collier was one of the 24 founding members of the Royal Society of Portrait Painters, of which he became Vice President. He was also a member of the Royal Institute of Oil Painters. He exhibited no fewer than 130 paintings at the Royal Academy and 165 at the Royal Society of Portrait Painters, as well as many others in galleries throughout the country and abroad. He was the author of The Primer of Art (1882), A Manual of Oil Painting (1886) and The Art of Portrait Painting (1905). He was awarded the OBE in 1920. He was the subject of The Art of the Honourable John Collier (1914) by W H Pollock, published by the Art Journal, which lists all his most important subjects between 1875 and 1914, whether portraits, or historical or other dramatic scenes. It has 50 illustrations and 6 colour plates of his works, and an interesting photograph of his studio.

The range of Collier's portrait subjects can be seen from the fact that, in 1893 for example, his subjects included the Bishop of Shrewsbury (Sir Lovelace Stamer), A Glass of Wine with Caesar Borgia, Sir John Lubbock FRS, A N Hornby (Captain of the Lancashire Eleven), A Witch, A Tramp, and the Bishop of Hereford (Dr Atlee).

His commissioned portrait of King George V as Master of Trinity House in 1901 when Duke of Cornwall and York, although very far from being his best work, shows the extent of his fashionable reputation.

Other subjects included two Lord Chancellors (the Earl of Selborne in 1882 and the Earl of Halsbury in 1898), the Lord Chief Justice Lord Alverstone (1912), and the Master of the Rolls (Sir George Jessel, 1881); Rudyard Kipling (1891); the painter (Sir) Lawrence Alma-Tadema (1884); the actors J L Toole (1887) and Mrs Kendal, Miss Ellen Terry and Mr Tree (in "The Merry Wives of Windsor", 1904); heads of houses such as the Master of Balliol (Professor Caird, 1904), the Warden of Wadham College, Oxford (G E Thorley, 1889) and the Provost of Eton (1898); the Speaker of the House of Commons (1898, one of relatively few political subjects); soldiers such as Field Marshal Lord Kitchener of Khartoum (1911) and Field Marshall Sir Frederick Haines (1891); two Indian Maharajahs, including the Maharajah of Nepal (1910); and scientists including Charles Darwin (1882), Dr Joule FRS (1882) and the artist’s father-in-law Professor Huxley (1891).