between Constantinople and the Lombards. Constantinople, the successor to the Roman Empire, was the capital of the Byzantine Empire and it had an administrative center in Ravenna, Italy. The Lombards were a powerful nomadic people in Italy. Gregory sought to placate the Lombards without alienating the Byzantines. His goal was to preserve the papacy's independence.

Gregory strengthened the Catholic Church by keeping it united and honest. He did this by combating Donatism (a schismatic movement) in North Africa and simony (buying and selling of offices) in Gaul.

And finally, Gregory was famous for his writings. He wrote about the lives of saints, Gospel homilies, and priceless letters.

Gregory I, or Gregory the Great as he became known, served as pope from 590 to 604 CE. When Gregory ascended to the papal throne, the remnants of what had been the Western half of the Roman Empire were in a state of chaos. The Italian peninsula was riven by famine, disease, and never-ending conflict. There was a dangerous power vacuum in Western Christendom which Gregory was determined to fill. To that end, Gregory established what became, more or less, the character of the medieval papacy: an institution devoted to the pursuit of temporal as much as spiritual ends. In other words, thanks to Gregory, the pope would not simply be the head of the Church; henceforth he would be a serious player in European power politics, a prince among princes.

Throughout Gregory's pontificate the papacy became actively involved in carrying out the functions of civil administration such as supplying grain to the towns, repairing roads and aqueducts, and maintaining an army. Increasingly, the people of Italy looked to the papacy to perform those tasks normally associated with secular rulers. This helped the papacy regain some of the prestige and moral authority lost since the fall of the Western Roman Empire in 476 CE. To a considerable extent, Gregory set in train a process whereby subsequent popes would attempt to recreate the Roman Empire in substance if not in form, using both the papacy's spiritual and temporal authority to cement its place in the medieval world.

Pope Gregory I is significant in a number of ways.

First, he is significant for having increased the secular power of the papacy.  Gregory took temporal power over an area that came to be known as the Papal States.  He did this as a way to help keep Rome safe from invasions of the time, but it ended up establishing the Church as a temporal power.

Second, Gregory did a great deal to spread the faith.  He is responsible for sending missionaries to Britain, for example, to convert the people of that Island.  

Finally, Gregory worked to create a unified Church with a unified belief system and liturgy.  He was energetic in trying to reduce the amount of heresy in the Church.  He made changes to the liturgy and encouraged their use across Europe.

In these ways, Gregory I was important for having increased the power and the unity of the Church.