It is stated, by some of his biographers, that he was sent as secretary of a Turkish mission.

In 1653, he was appointed the tutor of Cromwell's nephew; and, four years after, doubtless through the instrumentality of his friend Milton, he received the honorable appointment of Latin Secretary of the Commonwealth.

In 1658, he was selected by his townsmen of Hull to represent them in Parliament.

In this service he continued until 1663, when, notwithstanding his sturdy republican principles, he was appointed secretary to the Russian embassy.

On his return, in 1665, he was again elected to Parliament, and continued in the public service until the prorogation of the Parliament of 1675.
The boldness, the uncompromising integrity and irreproachable consistency of Marvell, as a statesman, have secured for him the honorable appellation of "the British Aristides." Unlike too many of his old associates under the Protectorate, he did not change with the times.