The Thirty Years' War consisted of many battles over a long period of time. It started with the Reformation and the split of the Catholic Church. A man named Martin Luther who was part of the Catholic Church started questioning their practices and how it conflicted with the Bible. This caused him to get kicked out and numerous people followed him, leading to the split of the Catholic Church. Numerous different churches began to get developed, including the Church of England after King Henry VIII wanted a divorce from his wife but the Catholic Church would not let him so he simply made his own. The split of the Catholic Church lead to a lot of tension and ultimately lead to many wars, including the infamous Thirty Years' War, which was actually fought including almost every single country in Europe.
The Thirty Years War began as a religious civil war between the Protestants and Roman Catholics in Germany that engaged the Austrian Habsburgs and the German princes. The war soon developed into a devastating struggle for the balance of power in Europe.
Islam has influenced Cardoba and West Africa in the east to Indonesia in the West so it's not easy to give a brief answer since the details are specific to social/cultural/economic context of local environs.
