[2] Fighting on the side of the Royalists in the English Civil War, he was captured following the fall of Bridgwater to the Roundheads in 1645.
The now-dominant Royalist faction on the island (buttressed by the arrival of many exiles from Great Britain) took power in a coup and seized control of the Governor, Philip Bell.
In Autumn of 1651 the Parliamentary authorities in England dispatched a fleet commanded by Sir George Ayscue to bring the recalcitrant island to heel.
Byam arrived in Surinam and quickly became the most powerful person in the colony (Lord Willoughby himself having returned to Europe), styling himself as a "colonel".
[10] Following the outbreak of the Second Anglo-Dutch War, the Dutch deployed a force under Admiral Abraham Crijnssen to capture Surinam.
Crijnssen's force arrived at the mouth of the Suriname River on 25 February 1667, and had Fort Willoughby under riverine bombardment and siege by the next day.
The Treaty of Breda, which brought an end to the war, was largely on the basis of uti possidetis, and saw Surinam ceded.
The English never regained sovereignty over Suriname, and Byam's authority in the area duly disintegrated.