Sir Michael Craig-Martin CBE RA (born 28 August 1941) is an Irish-born contemporary conceptual artist and painter.

[7] He gained an interest in art through one of the priests, who was an artist, and was also strongly impressed by a display in the Phillips Collection of work by Mark Rothko.

[8] In mid-1961 Craig-Martin studied art at the Académie de la Grande Chaumière in Paris,[10] and in the autumn he began a painting course at Yale University, where the teaching was strongly influenced by the multi-disciplinary experimentation and minimalist theories on colour and form of Josef Albers, a former head of department.

In the late 1970s he began to make line drawings of ordinary objects, creating over the years an ever-expanding vocabulary of images which form the foundation of his work to this day.

[13] The work consists of a glass of water standing on a shelf attached to the gallery wall, next to which is a text using an argument to explain why it is in fact an oak tree.

Nevertheless, on one occasion when it was barred by Australian Customs officials from entering the country as vegetation, he was forced to explain it was really a glass of water.

[14] From 1973, Craig-Martin was a tutor at Goldsmiths College and,[15] during the 1980s, was a significant influence on the emerging YBA generation, including Damien Hirst.

[17] Craig-Martin and his influence were described in an article in the Observer regarding the mentors of British art, entitled Schools of Thought.

An Oak Tree (1973), consisting of "an ordinary glass of water on an equally plain shelf, accompanied by a text in which Craig-Martin asserts the supremacy of the artist's intention over the object itself ... is now widely regarded as a turning point in the development of conceptual art".