The Livonian Brothers of the Sword was a Catholic military order established in 1202 during the Livonian Crusade by Albert, the third bishop of Riga. Pope Innocent III sanctioned the establishment in 1204 for the second time. The membership of the crusading order comprised warrior monks, mostly from northern Germany, who fought Baltic and Finnic polytheists in the area of modern-day Estonia, Latvia and Lithuania. Alternative names of the Order include Christ Knights, Swordbrothers, Sword Brethren, Order of the Brothers of the Sword, and The Militia of Christ of Livonia. The seal reads: +MAGISTRI ETFRM MILICIE CRI (Christi) DE LIVONIA.

A military order is a Christian religious society of knights. The original military orders were the Knights Templar, the Knights Hospitaller, the Order of Saint James, the Order of Calatrava, and the Teutonic Knights. They arose in the Middle Ages in association with the Crusades, both in the Holy Land, the Baltics, and the Iberian peninsula; their members being dedicated to the protection of pilgrims and Christians, as well as the defence of the Crusader states. They are the predecessors of chivalric orders.