The order of Canons Regular of the Penance (in Poland called the Marks and in Lithuania White Augustians) in the period in question was subjected to the diocesan authority. Bishops of Cracow and Vilnius alternately performed the duties of the highest superior, the Provost General of the order. This rigorous dependence aimed at improving discipline and practices in the order, which was not numerous but active in the field of ministry. In the years 1762-1794 the monks remained under the vigilant superiority of the Bishop of Vilnius, Ignacy Massalski. Provosty in Miedniki had a small number of ministers – apart from the parish priest (provost), there was another order priest and a preacher. The Provosty in Miedniki served a big parish, peopled mainly by Poles. The Holy Trinity church and the small monastery were built from wood. In 1778 and 1788 both buildings were destroyed by fire and each time they were rebuilt in wood. The renovation was co-financed by the longtime parish priest (1768-1774 and 1777-1800), Fr. Marcin Gałecki. Since the second half of the 17th century Guardian Angels Fraternity had its own altar at the church. Monks managed a parochial school for peasants’ and townsmen’s sons. The provosty in Miedniki supported itself from farmland (less than 70 ha) divided into three parts and peopled by a few families.