Teutonic Knights

Coat of arms of the Teutonic Order
Grand Master (Wikipedia)

The Teutonic Order, or the "Order of the Teutonic Knights of St. Mary's Hospital in Jerusalem", was originally formed to care for the sick and to aid travelers on their way to the Holy Land. As the Holy Lands were subject to some dispute, the Teutonic Knights evolved a martial arm. Shortly after the First Crusade, a faction of Ordo Militum Vindicis Intactae soldiers were embraced by the Teutonic Knights and disappeared into the Order.

In 1230 the Order was invited to "Christianize" the Old Prussians of north-east Germany and Poland. After subduing the area, the Order created the independant Monastic State of the Teutonic Knights that eventually formed the Duchy of Prussia in the 16th century.