Francis Geary was born in Surrey, England, in 1752, the eldest son of the naval officer Francis Geary and Mary Bartholomew Geary. His father had built a distinguished Royal Navy career through wartime commands and prize taking and later became Admiral Sir Francis Geary. The family’s position gave the younger Francis access to education, patronage, and the expectation of commissioned service within Britain’s imperial military establishment.

Geary was educated at Balliol College, Oxford. The surviving summaries identify him as a graduate, though they provide little detail about his course of study. Oxford offered a gentlemanly education in classics, religion, history, and intellectual discipline rather than specialized cavalry training. As an officer’s eldest son, he belonged to a social world in which family influence and the purchase of commissions could open a military career.

In 1773 Geary entered the British Army as a cornet in the 16th, or Queen’s, Light Dragoons. Cornet was the junior commissioned rank in a cavalry regiment, traditionally associated with carrying the troop’s standard. The position required horsemanship, personal courage, knowledge of drill, care of men and mounts, reconnaissance, and the performance of a gentleman officer’s social duties. Geary’s training continued within the regiment as he learned patrol work and cavalry administration.

The outbreak of the American war brought the 16th Light Dragoons across the Atlantic. By 1776 Geary was serving in the New York and New Jersey campaign. British forces used mounted detachments to scout roads, obtain intelligence, carry messages, protect foraging, and locate supplies. These missions placed junior officers at considerable risk in countryside where militia and armed civilians knew every lane.

Geary’s early life and career ended together on December 14, 1776. Leading a small reconnaissance patrol from the Pennington area toward Flemington, he rode into an ambush prepared by Hunterdon County militiamen under Captain John Schenck. Shot and killed at twenty-four, his body was concealed and later buried locally. He had advanced only from privileged education into the first stage of professional cavalry service before becoming the sole fatality in the action remembered by his name.