Editing Sliven (section)

=== Middle Ages ===
The area of Sliven was incorporated into the [[First Bulgarian Empire]] around 705 as part of the Slav-settled [[Zagore (region)|Zagore]], according to [[Tervel of Bulgaria|Tervel's]] treaty with the Byzantine Emperor [[Justinian II]]. A settlement was established on the area of Tuida, of which the etymology is unknown. The beginnings of the settlement weren't dated, but were before 870, when a lead seal of [[Boris I of Bulgaria|Boris I]] was discovered. The Bulgarians reconstructed the walls of the fortress and also the water supply at the northern gate. New buildings were built, some of which, have lined marble slabs made in [[Preslav]]'s stonemasonry workshops.

Paleoornithologist Zlatozar Boev discovered bone remains of 14 species of wild and domestic birds in Hissarlaka from the 10th-12th centuries. The findings of [[Hawk eagle]] ([[Aquila fasciata]]) and [[grouse]] ([[Tetrao urogallus]]) are among the rarest in the country.

The town continued to exist after the dissolution of the first empire. The Pechenegs briefly controlled it in mid-10th century, after which it began to decline. In 1153, the town was rebuilt. The fortress was abandoned and ceased.

During the [[Second Bulgarian Empire]], twenty-four monasteries were built in its vicinity, which formed a complex. Under Tsar [[Ivan Alexander of Bulgaria|Ivan Alexander]], Sliven was a town near the [[Byzantine Empire]].<ref>Димитър Ангелов, Въпросът за политическите емигранти в отношенията между Византия и средновековна България // В: Античная древность и средние века. – Вып. 10. – 1973. – С. 121.</ref> During the [[Bulgarian–Ottoman wars|Ottoman invasion of Bulgaria]], the medieval town was destroyed and the monasteries were burnt. The city was known as "İslimye" by the Turks.