Answer:A Challenge to the Church in Rome
In art history, the 16th century sees the styles we call the High Renaissance followed by Mannerism, and—at the end of the century—the emergence of the Baroque style. Naturally, these styles are all shaped by historical forces, the most significant being the Protestant Reformation’s successful challenge to the spiritual and political power of the Church in Rome. For the history of art this has particular significance since the use (and abuse) of images was the topic of debate. In fact, many images were attacked and destroyed during this period, a phenomenon called iconoclasm.
The Protestant Reformation
Today there are many types of Protestant Churches. For example, Baptist is currently the largest denomination in the United States but there are many dozens more. How did this happen? Where did they all begin? To understand the Protestant Reform movement, we need to go back in history to the early 16th century when there was only one church in Western Europe - what we would now call the Roman Catholic Church - under the leadership of the Pope in Rome. Today, we call this "Roman Catholic" because there are so many other types of churches (ie Methodist, Baptist, Lutheran, Calvinist, Anglican - you get the idea).
The Church and the State
So, if we go back to the year 1500, the Church (what we now call the Roman Catholic Church) was very powerful (politically and spiritually) in Western Europe (and in fact ruled over significant territory in Italy called the Papal States). But there were other political forces at work too. There was the Holy Roman Empire (largely made up of German speaking regions ruled by princes, dukes and electors), the Italian city-states, England, as well as the increasingly unified nation states of France and Spain (among others). The power of the rulers of these areas had increased in the previous century and many were anxious to take the opportunity offered by the Reformation to weaken the power of the papacy (the office of the Pope) and increase their own power in relation to the Church in Rome and other rulers.
Keep in mind too, that for some time the Church had been seen as an institution plagued by internal power struggles (at one point in the late 1300s and 1400s church was ruled by three Popes simultaneously). Popes and Cardinals often lived more like kings than spiritual leaders. Popes claimed temporal (political) as well as spiritual power. They commanded armies, made political alliances and enemies, and, sometimes, even waged war. Simony (the selling of Church offices) and nepotism (favoritism based on family relationships) were rampant. Clearly, if the Pope was concentrating on these worldly issues, there wasn't as much time left for caring for the souls of the faithful. The corruption of the Church was well known, and several attempts had been made to reform the Church (notably by John Wyclif and Jan Hus), but none of these efforts successfully challenged Church practice until Martin Luther's actions in the early 1500s.