In the Middle Ages, a commandery (rarely commandry) was the smallest administrative division of the European landed properties of a military order. It was also the name of the house where the knights of the commandery lived. The word is also applied to the emoluments granted to a commander. They were the equivalent for those orders to a monastic grange. The knight in charge of a commandery was a commander.
A military order (Latin: Ordo militaris) is a Latin Catholic religious order of knights. The original military orders were the Knights Templar, the Knights Hospitaller, the Order of the Holy Sepulchre, the Order of Saint James, the Order of Calatrava, and the Teutonic Knights. They arose in the Middle Ages in association with the Crusades – the Crusader states (mainly the Kingdom of Jerusalem in the Holy Land), the Baltics, and the Iberian peninsula; their members being initially dedicated to the protection of Christian pilgrims, and eventually to the defence of the Crusader states and the conquest of non-Christian or even non-Catholic lands. They are the predecessors of chivalric orders.
Most members of military orders were laymen who took religious vows, such as of poverty, chastity, and obedience, according to monastic ideals. The orders owned houses called commanderies all across Europe and had a hierarchical structure of leadership with the grand master at the top.