For the local administration of church affairs, the Catholic world was divided under the pope into several territorial subdivisions, (1) The patriarchates had been under patriarchs who had their sees [Footnote: "See," so called from the Latin _sedes_, referring to their seat or chair of office. Similarly our word "cathedral" is derived from the Latin _cathedra_, the official chair which the bishop occupies in his own church.] in such ancient Christian centers as Rome. Jerusalem, Alexandria, Antioch. and Constantinople. (2) The provinces were divisions of the patriarchates and usually centered in the most important cities, such as Milan, Florence, Cologne, Upsala, Lyons, Seville, Lisbon, Canterbury, York; and the head of each was styled a metropolitan or archbishop. (3) The diocese--the most essential unit of local administration--was a subdivision of the province, commonly a city or a town, with a certain amount of surrounding country, under the immediate supervision of a bishop. (4) Smaller divisions, particularly parishes, were to be found in every diocese, embracing a village or a section of a city, and each parish had its church building and its priest. Thus the Catholic Church possessed a veritable army of officials from pope and cardinals down through patriarchs, archbishops, and bishops, to the parish priests and their assistants, the deacons. This hierarchy, because it labored _in the world_ (_sæculo_), was called the "secular clergy." [Sidenote: "Regular" Clergy] Another variety of clergy--the "regulars"--supplemented the work of the seculars. The regulars were monks, [Footnote: The word "monk" is applied, of course, only to men; women who followed similar rules are commonly styled nuns.] that is, Christians who lived by a special _rule_ (_regula_), who renounced the world, took vows of chastity, poverty, and obedience, and strove to imitate the life of Christ as literally as possible. The regular clergy were organized under their own abbots, priors, provincials, or generals, being usually exempt from secular jurisdiction, except that of the pope. The regulars were the great missionaries of the Church, and many charitable and educational institutions were in their hands. Among the various orders of monks which had grown up in the course of time, the following should be enumerated: (1) The monks who lived in fixed abodes, tilled the soil, copied manuscripts, and conducted local schools. Most of the monks of this kind followed a rule, or society by-laws, which had been prepared by the celebrated St. Benedict about the year 525: they were called therefore Benedictines. (2) The monks who organized crusades, often bore arms themselves, and tended the holy places connected with incidents in the life of Christ: such orders were the Knights Templars, the Knights Hospitalers of St. John and of Malta, and the Teutonic Knights who subsequently undertook the conversion of the Slavs. (3) The