In the early Middle ages (V-VII c A.D.) Surkhandarya Province was a part of the large historical-cultural region Tokhariston including in it the main part of the ancient Bactria. Tokhariston consisted of a great number of possessions two of which Da-mi (Termez) and Chi-o-yan-na (Chaganian) were on the territory of Surkhandarya Province. After the collapse of the Kushan state this territory in the second half of the III –IV c became a part of domains of the Sasanid Iran. By the middle of the Vc the Ephtalite state was formed, Chaganian was a part of it for almost 70 years. In 667 the Arabs made their first raid to Chaganian and in nine years the governor-general of Khorasan Said ibn Osman entered Termez. But those were short term success: Arabs did not pursue more serious goals yet.