Bohun was born probably in England between 1575 and 1585. An acquaintance later wrote that Bohun had been “a long time brought up amongst the most learned Surgeons, and Physitions in Netherlands.” Most likely he received his medical education at Leiden, but nothing of his youth or education is definitely known. Bohun, whose surname contemporaries often spelled “Bohune” or “Boone,” sailed for Virginia on April 1, 1610, as personal physician to the new governor, Thomas West, baron De La Warr. Within a month after they arrived in Jamestown on June 10, 1610, Bohun had treated the governor’s fever with bloodletting, which De La Warr believed had saved his life. Bohun soon depleted his medical chest treating colonists’ frequent illnesses, and during the nine and one-half months he was in the colony he experimented with indigenous native plants and minerals to ascertain their medicinal properties. He used sassafras to purge phlegm, employed a white clay to fight fevers, used the saps of gum trees and white poplar to make a balm for healing wounds, and compounded a medicine for dysentery from myrtle fruit.