Roman Emperor Henry IV and furthered the friction caused in the Investiture Conflict. Catholic Church in the Middle Ages The expanded practice continued through the Middle Ages within the European feudal system. This same customary method became adopted by the Catholic Church. The church's revenue streams came from, amongst other things, rents and profits arising from assets gifted to the church, its endowment, given by believers, be they monarch, lord of the manor or vassal, and later also upon tithes calculated on the sale of the product of the people's personal labour in the entire parish such as cloth or shoes and the people's profits from specific forms of likewise God-given, natural increase such as crops and in livestock. Initially the Catholic Church granted buildings, grants of land and greater and/or lesser tithes for life but the land was not alienated from the dioceses. However the Synod of Lyon of 567 annexed these grants to the churches. By the time of the Council of Mainz of 813 these grants were known as beneficia. Holding a benefice did not necessarily imply a cure of souls although each benefice had a number of spiritual duties attached to it. For providing these duties, a priest would receive "temporalities". Benefices were used for the worldly support of much of its pastoral clergy – clergy gaining rewards for carrying out their duties with rights to certain revenues, the "fruits of their office". The original donor of the temporalities or his nominee, the patron and his successors in title, held the advowson (right to nominate a candidate for the post subject to the approval of the bishop or other prelate as to the candidate's sufficiency for the demands of the post). Parish priests were charged with the spiritual and temporal care of their congregation. The community provided for the priest as necessary, later, as organisation improved, by tithe (which could be partially or wholly lost to a temporal lord or patron but relief for that oppression could be found under canon law). Some individual institutions within the church accumulated enormous endowments and, with that, temporal power. These endowments sometimes concentrated great wealth in the "dead hand" (mortmain) of the church, so called because it endured beyond any individual's life. The church was exempt from some or all taxes. This was in contrast to feudal practice where the nobility would hold land on grant from the king