The Thessaloniki Region

The Thessaloniki region, in the northern part of Aegean Macedonia around the modern city of Thessaloniki, known in Bulgarian as Solun, played a key role in the Bulgarian state's military ambitions from the time of the First Bulgarian Empire.
As early as the reign of Khan Krum (803–814), the Bulgarian army reached the walls of Thessaloniki as part of large-scale offensives against Byzantium in the early ninth century. In 904, under Tsar Simeon the Great (893–927), the city was again threatened by Bulgaria. Negotiations between Byzantium and Bulgaria resulted in a peace treaty under which a substantial part of the Thessaloniki region and the western Macedonian lands were ceded to Bulgaria.
During the reign of Tsar Samuel (997–1014), Thessaloniki remained a key objective of Bulgarian expansion towards the south-west. The city was an important Byzantine administrative, commercial and spiritual centre and a constant target of military pressure. The Bulgarians temporarily gained control of its surroundings, while the city itself endured several sieges by Samuel's forces.
In 995, Samuel's brother Aaron led a campaign against Thessaloniki that ended in a heavy defeat. A little later, around 1004–1009, Bulgarian forces again struck around the city as part of their resistance to the advance of the Byzantine emperor Basil II the Bulgar-Slayer.
The Thessaloniki region also holds a special place in Bulgaria's spiritual history. It was the birthplace of the brothers Cyril and Methodius, creators of the Glagolitic alphabet and educators of the Slavic peoples. Their legacy is deeply rooted in Bulgarian cultural identity and Orthodox tradition.
After Samuel's death in 1014 and Byzantium's final subjugation of Bulgaria in 1018, Thessaloniki and its region remained firmly under Byzantine control. Nevertheless, the memory of Bulgarian campaigns and the temporary presence in the region survives as part of national memory.