Kozhuh area prove that there is no continuity between this city, located in the lands of the Thracian Sinti tribe, and modern Petrich, but a hiatus of several centuries. The earliest settlements on the site of the city appear only in the X - XI century. Petrich was formed as a significant settlement and regional center only at the end of the XII - XIV century. The Middle Ages The Petrich region was annexed to the Bulgarian state in 837 as a result of the war of the Bulgarian Khan Presian against Byzantium. At the end of the 10th and the beginning of the 11th century, the lands around Petrich occupied an important military-strategic place in Samuel's state. In 1014, not far from today's town, in the so-called Kleidion gorge, a decisive battle took place between the Bulgarian troops led by Tsar Samuel and the troops of the Byzantine Emperor Basil II. The remains of Samuel's fortress still remind of the blinding of the captured 14,000 Bulgarian soldiers. For this act the Byzantine emperor Basil II received the nickname Bulgarian Assassin. During the period XII - XIV century Petrich became a strong fortress - part of the fortification system in southwestern Bulgaria. This is evidenced by the remains of the medieval fortress Gyaur Kalesi, around which the city originally arose. At least in the XIII - XIV century the city consists of two parts - a fortress, i.e. fortified city core and unfortified outer city, but with entrance-exit arteries guarded by towers. Petrich was first mentioned in written sources in the deeds of the Serbian magnates Jovan Dragaš and Konstantin Dragaš, who in 1376 - 1377 donated here properties to the Russian monastery "St. Pantaleimon" in Mount Athos. The town fell under Ottoman rule after 1395, when together with its surroundings it was included in the Kyustendil Sandzak as a center of independent Nahiyah. In the Ottoman Empire During the years of Ottoman rule, Petrich acquired a Muslim appearance. The Bulgarians fled to the opposite Ograzhden mountain to stay away from the arbitrariness of the Turks. The Ottoman traveler Evliya Çelebi visited Petrich in 1652 and reported that the palanquin had 240 not very well-developed houses with gardens. There are all two neighborhoods with a mosque, a chapel, two inns and only one bathroom. The center is a kaaza with 80 villages. There are 50 shops, which suggests the level