The Battle of Adrianople occurred on April 14 1205 between Bulgarians under Tsar Kaloyan of Bulgaria, and Crusaders under Baldwin I. It was won by the Bulgarians after a skillful ambush using the help of their Cuman and Greek allies. Around 300 knights were killed, including Louis of Blois, Duke of Nicaea and Baldwin was captured, blinded, and later died in captivity.
The second Battle of Adrianople (August 9 378) was fought between a Roman army led by the Roman Emperor Valens and Gothic rebels (largely Thervings as well as Greutungs, non-Gothic Alans, and various local rebels) led by Fritigern. The battle took place near Adrianople and ended with an overwhelming victory for the Goths.Ammianus Marcellinus, Historiae, book 31, chapters 12-14.Zosimus, Historia Nova, book 4.
The Battle of Adrianople resulted in tactical victory for the Ottoman Turks. It marked the beginning of the end of Byzantine presence in the Balkans. Immediately after the battle, the Ottomans moved their capital from Bursa to Adrianople.