He became involved in English attempts to settle Providencia Island in the late 1630s, and returned to England in 1641 after financial reverses and probable religious differences with other members of the Massachusetts ruling elite.
While White sought new sources of funding in London, Humphrey circulated in the Puritan circle of his brother-in-law the Earl of Clinton.
[2] The company acquired a grant from the Plymouth Council for New England for land roughly between the Charles and Merrimack Rivers.
A number of Clinton's associates, notably John Winthrop, Thomas Dudley, Richard Bellingham, and Simon Bradstreet, were also drawn to the idea of migration to North America.
[5] He remained actively involved in the Company in London, and assisted in defending its charter against attacks levied by Sir Ferdinando Gorges in 1633.
Possibly dissatisfied with the religiously intolerant nature of the Massachusetts government, Humphrey became involved in a scheme headed by Lord Say and Sele to colonise Providencia Island in the Caribbean.
In 1640 Lord Say and Sele offered, and Humphreys accepted, appointment as governor of the Providence Island colony.
Humphreys aligned himself with the Independent faction associated with Henry Vane the Younger and others during the English Civil War.