It is unclear if he was troubled by the large commission he received from John Wilson Croker or by an unrequited love for a young woman who was the subject of one of his portraits.

[2] In 1816 he exhibited Hercules throwing Lychas into the Sea, and in 1817 two works, Portrait and Christ taken down from the Cross.

He visited the studio of the sculptor Joseph Nollekens regularly, modelling from antique heads.

Foster was considered well-connected and was popular in society, but fellow painter James Northcote believed this hindered him in becoming a great artist as he spent too much time socialising.

Foster had been commissioned to paint the scene of Louis XVIII receiving the Order of the Garter at Carlton House, for which he produced a number of studies.