The Castle of Indolence was published early in the summer of 1748, four months after the poet's death. The work was a slow and leisurely composition, which took nearly fifteen years to complete.

The poem consists of 158 stanzas, divided into two cantos. It is presented as an allegory and was professedly written in imitation of The Faerie Queene.

The origin of the poem appears to be the frequent remonstrances of Thomson's friends about the poet's well-known indolence, regarding both life and composition.

In its finished state, it may be regarded as an apology and a warning. The apology, mostly playfully urged, is for Thompson's own indolence; the warning is meant to discourage the indulgence of indolence in others.