During the 18th century, all states commonly hired foreign soldiers, especially Britain; during the Seven Years' War, they comprised 10% of the British army and their use caused little debate. When it became clear additional troops were needed to suppress the revolt in America, it was decided to employ mercenaries. There were several reasons for this, including public sympathy for the Patriot cause, an historical reluctance to expand the British army and the time needed to recruit and train new regiments. An alternate source was readily available in the Holy Roman Empire, where many smaller states had a long tradition of renting their armies to the highest bidder. The most important was Hesse-Cassel, known as "the Mercenary State".