What was the relationship between Serbia and Bulgaria in the early Middle Ages?

In the 13-14 century, Serbia and Bulgaria were in a state of feudal fragmentation. At that time, Byzantium proposed to conclude an alliance with the Bulgarians and Serbs against the Ottoman Turks, but they rejected the offer of Byzantium, arguing that when the enemy appears, then we will defend ourselves against him.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.