In the 6th and 7th centuries, the Roman town became subject of Slavic migration . The Strymonites, a Sclavene tribe, adopted their name after the Strymon river (Struma). The Strymonites were independent until the 9th century, followed by a Byzantine reconquest. Later on, the Strumica region was conquered by Bulgarian Khan Presian (836–852). The Strumica region remained part of the Bulgarian state throughout a period of more than 150 years right up until 1014, when it was retaken by the Byzantines. In the 11th century, written sources begin to refer to the town with its Slavic name as "Strumica".