The Janissaries were elite infantry units that formed the backbone of the Ottoman Empire's military from the 14th to the 19th centuries. Originally composed of Christian boys taken from their families through the devshirme system, they were converted to Islam and trained as soldiers. The Janissaries were known for their discipline, loyalty, and advanced military tactics. As the empire expanded, the Janissaries played a crucial role in many battles and conquests. They were equipped with firearms and were among the first military units to use gunpowder effectively. Over time, their power grew, leading to political influence and eventual decline as the empire faced modernization challenges.