He was born to the Reverend Johannes Ritzema and Hiltje Dijkstra in Kollum, a village in the Friesland province of the Dutch Republic.
[1] He went from there to study divinity in the Netherlands, but was uninterested, and ended up enlisting in the Prussian army, where he likely saw service in the Seven Years' War.
According to charges filed by Stirling, Ritzema was lax in maintaining order and discipline in his regiment, which was two hours late for a parade review on July 1, 1776.
The bad blood appears to have continued, for by November 1776, possibly during or after the Battle of White Plains, Ritzema deserted and joined the British Army.
[3][4] In May 1778, as a lieutenant colonel in the British army, he raised a few companies of an organization called the Royal American Reformers.