Hessians (US: or UK: ) were German soldiers who served as auxiliaries to the British Army during the American Revolutionary War. Britain had a small army, most of which were needed at home. It decided to rent regiments. Most governments refused, but several small German states such as Hesse had a reputation as "mercenary states" and rented regiments to the British for combat duty. The Patriots often called the hired German soldiers "Hessians" and denounced them all as "mercenaries" who were not fighting for their native land.
In his history of the Hessians, Rodney Atwood says, "By common usage, however, the Hessians have been called mercenaries. In this work I refer to them as both auxiliaries and mercenaries."
The term is an American synecdoche for all Germans who fought on the British side, since 65% came from the German states of Hesse-Kassel and Hesse-Hanau. Known for their discipline and martial prowess, around 30,000 Germans fought for the British during war, comprising a quarter of British land forces.Although frequently referred to by scholars as mercenaries, Hessians were in terms of 18th century legal thought distinguished as auxiliaries. Unlike mercenaries, who served a foreign government on their own accord, auxiliaries were soldiers hired out to a foreign party by their own government, to which they remained in service. As a source of funding throughout the 18th century, many small poor German states regularly rented out the services of their troops to fight in wars in which they were neutral and had no other involvement. Like most auxiliaries of this period, Hessians served with foreign armies as entire units, fighting under their own flags, commanded by their usual officers, and wearing their existing uniforms.
Hessians played a key role in the Revolutionary War. They served with distinction in many battles, particularly in the northern theater, most notably at White Plains and Fort Washington. The added manpower and skill of German troops is credited for greatly sustaining the British war effort, but it also outraged colonists and increased support for the Patriot cause. The use of "large armies of foreign mercenaries" was one of the 27 colonial grievances against King George III in the United States Declaration of Independence, while the Patriots
used the deployment of Hessians to support their claims of British violations of the colonist's rights.