As the poem’s title suggests, Marvell wrote “An Horatian Ode upon Cromwell’s Return from Ireland” in the form of a Horatian ode. The Horatian ode, as it has survived, dates at least as far back as 20 B.C.E and the Roman poet Horace, for whom the form is named. The Horatian ode finds its roots in the earlier Greek Aeolic ode. Both forms, in their original literary contexts, express tones of formality and tranquility. Marvell’s use of the form further connects Cromwell to the Roman figures, history, and ideas that Horace originally wrote about.

Formally, Horatian odes have few defining features. In English, the only formal criteria are that the poem has more than one stanza and that each stanza is structured according to the same meter, number of lines, and rhyme scheme. This means that Horatian odes are odes created from uniformly structured stanzas. Though Marvell’s ode was not divided into stanzas in its original publication, the poem’s rhyme scheme and structure suggests that it was intended to be divided into stanzas of four lines. In this way, Marvell’s poem is best understood as comprising of 30 quatrains, or stanzas of four lines.