The Ottoman army's classical battle formation emerged in the late 14th century, but it was not yet the powerful force that would later intimidate Europe and Asia. At the Battle of Kosovo, the Ottomans suffered significant losses and only managed to gain the upper hand towards the end of the battle. The Janissary Corps and other elite units were still too small to have a significant impact on the outcome.
The different units of the Ottoman army had their own weaknesses. The Azabs, with their light armor, were no match for the heavily armored Serbian infantry cavalry. The Akinjis, who were essentially raiders, lacked the conventional cavalry capacity to make a difference. The Timarli Sipahi Corps was still in its early stages and struggled with maintaining unit cohesion during battles. However, the individual actions of the Sultan's son, Şehzade Bayezid, on the right wing ultimately led to the Ottoman victory.
Seven years later, the Ottomans applied the lessons they learned from Kosovo and achieved a decisive victory over the Crusader forces at the Battle of Nicopolis. For the first time, the Janissaries played a crucial role in the battle, employing successful defensive tactics such as the use of sharpened stakes and ditches to annihilate the Crusader heavy cavalry. The Ottomans' strategic planning and tactical maneuvers allowed them to outmaneuver their enemies and secure a significant victory. The battle marked a turning point in the history of the Ottoman army, as they began to develop a more capable and cohesive force. The Ottomans also demonstrated their ability to adapt and improve, using infantry tactics and cavalry units to great effect. The use of stakes and ditches as defensive measures was particularly effective, and the Ottomans' heavy cavalry played a key role in the battle.
