How did the warfare look like in medieval times? What is the largest known battle on sea from that time?
Medieval battles were extremely organized and logistical battles that involved thousands of soldiers and widespread organization. The main components of a typical Medieval battle would be the foot soldiers, who were usually peasants or poor members of society, the knights, who were hired soldiers and members of nobility who fought on horseback, archers, who were either peasants or hired mercenaries, and artillery such as catapults or trebuchets.
Pitched battles usually consisted of long lines of foot soldiers fighting against one another whilst the knights harassed the sides and backs of the enemy army in order to scare and demoralize the soldiers. Archers would stand behind the foot soldiers and fire at the enemy as would artillery, which was usually widely inaccurate and mainly used for siege warfare.
In regards to the largest naval battle, as records from this period are extremely scant and often unreliable, although a number of naval battles could be given the title of largest naval conflict. The battle of Sluys between English and French forces in 1380 was one of the largest naval battles of the century, with over 300 naval vessels being involved in the conflict.
The Battle of Nicomedia Bay in 718 was also an important naval encounter of the period, where the Byzantine Empire used Greek Fire to destroy or rout over 700 Umayyad ships which had come to aid in the siege of the city of Constantinople, which collapsed after this defeat.