The Ottoman army's classical battle formation, which emerged in the late 14th century, was still in its formative stages and had not yet developed into the formidable force that would later inspire fear across Europe and Asia. The Battle of Kosovo, fought in 1389, was a prime example of the Ottoman army's early struggles, as they suffered significant losses and only managed to gain the upper hand towards the end of the battle. The Janissary Corps, an elite infantry unit, and other Kapikulu units were still too small to have a substantial impact on the outcome of the battle.
The various units of the Ottoman army had distinct weaknesses that hindered their overall performance. The Azabs, lightly armored and mobile, were no match for the heavily armored Serbian infantry cavalry. The Akinjis, essentially raiders with limited conventional cavalry capacity, struggled to make a significant impact. The Timarli Sipahi Corps, still in its infancy, grappled 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. The Ottomans' use of strategic planning and tactical maneuvers allowed them to outmaneuver their enemies and secure a significant 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' ability to adapt and improve, using infantry tactics and cavalry units to great effect, marked a turning point in the history of the Ottoman army. The use of heavy cavalry and defensive measures, such as stakes and ditches, was particularly effective, and the Ottomans' capable and cohesive force began to take shape. The Ottomans also demonstrated their ability to use strategic planning and tactical maneuvers to outmaneuver their enemies.
