Born in 1909 Claessen spent his first thirty eight years of his life in Ceylon (Sri Lanka). He belonged to a family who had a strong inclination towards visual arts. He began to paint only at the age of 29 after he joined the Port Commission in Colombo as a Draughtsman.
A founding member of the 43 group, Claessen, came to public notice through the publication in 1946 ‘Jataka’ a little book of drawings by him, which was edited by Ian Goonetileke. Arther van Langenberd provided the Foreword in which he stated ‘The appreciation of a drawing after the first sensation is past, creates a longing for serener, more lasting qualities which the artist is called upon to satisfy. The drawings of George Claessen possess these qualities” (Weereratne, 1993,59).
Some of his art was inspired by Chinese brush drawings and Japanese woodcut. Some others show a modelling of typical European draughtsmanship. His work is mainly dominated by a subtle intimacy and a suggestive use of line which captures form and explores movement (Dharmasiri, 2001)
George Classesn’s works came to public attention at the regular exhibitions of the 43 group. In the late 1940s he moved to Melbourne where he experimented with abstract painting. He then moved to London. He exhibited at the Group’s first exhibition at the Imperial Institute in 1952 with six others of the 43 Group. Claessen participated in the Venice Biennale of 1956 and at the fifth Biennale at the Messeu de Arte Moderna in Sao Paulo, Brazil in 1959, where he also won an award. Following this he held a one-man exhibition at the New Vision Centre Gallery, London in 1962.
He has published two books of mainly traditional poems; Poems of a Painter published by Mitre Press in 1967 and Poems about Nothing published by Arthur Stockwell in 1981.