During the Middle Ages, the proprietary church (Latin ecclesia propria, German Eigenkirche) was a church, abbey or cloister built on private ground by a feudal lord, over which he retained proprietary interests, especially the right of what in English law is "advowson", that of nominating the ecclesiastic personnel. In a small parish church this right may be trivial, but in the German territories of Otto the Great it was an essential check and control on the church, through which the Holy Roman Emperor largely ruled.
In the later Roman Empire the church had been centrally organized: all monasteries and churches within a diocese, including their personnel and their properties, were under the jurisdiction of the local bishop. Ulrich Stutz has demonstrated that the institution of the proprietary church existed particularly in areas that had never been Roman, among the Irish and the Slavs, and in the Eastern Roman Empire, but the proprietary church is best known in Germany, where the Grundherr, the land lord who had founded the church on his property and endowed it from his lands, maintained the right of investiture, as he was the advocatus (German Vogt) of the fief, and responsible for its security and good order. In the 9th and 10th centuries the establishment of proprietary churches in Germany swelled to their maximum. The layman who held the position was a lay abbot. The altar was the legal anchor to which the structures, the land, the rights and ties were attached. The proprietor and his heirs retained unabated legal rights to the ground on behalf of the saint whose relics lay beneath the altar. "He could sell, lend or lease the altar, leave it to his heirs, use it for dower, or mortgage it, provided that a church, once dedicated, continued to be used as a church." The proprietary right could be granted away or otherwise alienated, even for a sum of money, which compromised the position of the spiritual community that it contained. In such a situation, simony, the outright purchase of an ecclesiastic position through payment or barter, was an ever-present problem, one that was attacked over and over in all the synods of the 11th and early 12th century Gregorian reforms, and fuelled the Investiture Controversy.
Within the Carolingian empire, the rules concerning proprietary churches had been expressly formulated in the ninth century, at the reforming councils of 808, under Charlemagne and of 818/9, under Louis the Pious. Then proprietary churches had been officially recognized, but the capitulations identify some of the associated excesses, for it was agreed that the proprietor should not appoint nor depose priests without the assent of the bishop, nor appoint unfree persons. Every church was to be provided with a manse and its garden that were free of seigneurial dues, where the priest could support himself, providing spiritual services. The rights of proprietarial founders were also delimited and protected, for the bishop could not refuse to ordain a suitable candidate; the legislation also protected the founder's right over proprietary abbeys to appoint a member of the founding family.
The Royal peculiars have remained proprietary churches until today.
A Medieval example is the church of Littleham, Devon, mentioned in 1422. 
- Uta-Renate Blumenthal, The Investiture Controversy: Church and Monarchy from the Ninth to the Twelfth Century, 1988:5.
- Blumenthal 1988:5.
- Blumenthal 1988:5.
- Plea Rolls of the Court of Common Pleas; National Archives; CP40/647; http://aalt.law.uh.edu/AALT1/H6/CP40no647/aCP40no647fronts/IMG_0172.htm; 5th & 6th entries, with Devon in the margin
- Ulrich Stutz: Ausgewählte Kapitel aus der Geschichte der Eigenkirche und ihres Rechtes. Böhlau, Weimar 1937
- Ulrich Stutz: Die Eigenkirche als Element des mittelalterlich-germanischen Kirchenrechts. Wissenschaftl. Buchgesellschaft, Darmstadt 1964
- Ulrich Stutz, Hans Erich Feine: Forschungen zu Recht und Geschichte der Eigenkirche. Gesammelte Abhandlungen. Scientia, Aalen 1989, ISBN 3-511-00667-8
- Ulrich Stutz: Geschichte des kirchlichen Benefizialwesens. Von seinen Anfängen bis auf die Zeit Alexanders III. Scientia, Aalen 1995, ISBN 3-511-00091-2 (Ergänzt von Hans Erich Feine)