Working from biblical precedent (the divinely-ordainment of Saul and David), the Roman Catholic church was the inventor, and proponent, of the "Divine Right of Kings," the concept that kings ruled by God's will. This concept has a curious background. When the Christian church first encountered the Germanic tribes during the 5th Century, the Christians thought of themselves as a very Roman institution. Christianity was born under Roman auspices and had, since the 4th Century, been the official religion of the Roman Empire. The Germans were usually Christian themselves, albeit often of heretical varieties. So the church was one Roman institution that survived German depredations intact, gradually triumphing over the miscellaneous versions of Christianity which the Germans had practiced. By the 7th Century, most of the Germans had been converted to orthodox Christianity, especially the ones living in former Roman territory. The conversion wasn't effected soley by religious arguments. The Church also pointed out that the German rulers could benefit greatly by linking their fortunes to the See of Peter . In effect, the Church had the say-so as to who had the "divine right" to the throne. The German kings got the message, and the blessings of the Church. This arrangement caused trouble from time to time, when a pope decided he had to relieve someone of that right (such as Frederick von Hohenstaufen), but it usually worked pretty well and lasted, a very long time.