Conflicts between the Catholic Church and European monarchs are nothing new. Foremost among this timeless conflict is the Investiture Controversy, beginning in 1076 due to a feud between Pope Gregory VII and King Henry IV of Germany and ending in 1122 with the Concordat of Worms. Kings had been appointing bishops and abbots, a job meant to be for the Pope. The Concordat sought to alleviate the conflict by stating the Church had the sole ability to select the bishops and appoint abbots of monasteries. However, this crisis continued on centuries after as monarchs sought to appoint, or publicly support, clergy to their court. Some monarchs also had very tense relationships with the Church, resulting in a secular vs ecclessiastical conflict. Many different documents help identify this conflict, most of which are letters exchanged between the monarch’s ambassadors and the clergy of the Church. Monarchs across Europe, such as Emperor Frederick II, Emperor Charles V,  and Philip II, exemplify this pattern of conflict. Emperor Frederick II had a complex relationship with the papacy and was eventually excommunicated three times, and will be seen in letters from Church officials and even the Pope himself. Charles V saw the Church as vital to maintaining his empire, but internal conflicts weighed on him. Philip II saw the Church as an obstacle when pursuing his duty as “defender of Christendom,” and can be seen through letters between his ambassadors and Church officials.