|After the Victory of Malazgirt, Türkmen communities intensively migrated to the newly conquered regions of the Anatolia. Birecik and its vicinity was inhabited by the Seljukî Turks. Kutalmış oğlu Süleyman Şah, who preserved the region as his military base, organized his military attacks to the Northern Syria from this region. Invaded by the Crusades in 1 1 10, Bire cik was taken over by Artuklar in 1 151; and it was reconstructed and turned out to be a Turco- Islamic city. The city, administered by Artuk Şehzades, was annexed to MemlUks who dominated the region later. During the Memlûk Era the city was reorganized as a border city and it prospered with its selected masterpieces, Birecik, which was the domain of the Ottoman rule in 1516, was reorganized administratively as a Sancak of Eyalet-i Arab. The city Birecik turned out to be the capital of the Sancak due to its political and economic significance, later, it was annexed to the Halep Eyaleti, and to the Rakka Eyaleti in 1587. During the XVI. century, the city Birecik consisted of the seven quarters. It ranked the sixth largest city of the South Eastern Anatolia; in terms of its population. The majority of the population was Muslims except for a few christians living in Muslim quarters. They ceased to exist entirely in 1584. The estimated population of the city totalled 3932 in 1520, decreased by 28% and totalled 2778 in 1536. Showing an increasing trend later, the population of the city increased by 91.5 % and amounted to 4362 during the years 1536 - 1584. By means of the vessels, constructed at the dock established in Birecik, every kind of trading goods, including the military material and personnel were transported via Euphrates to the southern regions; and the related material was forwarded for the vessels constructed in the Persian Gulf. These developments paved the way for physical economic and social well-being of the city. The revenues of Birecik Port were 180.000 akçe in 1536; 200.000 akçe in 1584. The dock located in Birecik which employed about 1000 temporary workers from the other regions for the construction of vessels, was the largest industrial establishment of the South- Eastern Anatolia during the XVI. century. The sancak of Birecik consisted of Birecik kazası and Birecik and Suruç nahiyesi annexed to Birecik kazası. After the annexation of Rumkale Sancağı to Birecik sancağı the number of the kazas reached two in 1523. It was understood that Birecik and Suruç nahiyesi were and the domain of Birecik kazası, while Ank, Araban and Merzuman nahiyesi were attached to Rum kale kazası and belonged to the sancak accordingly. However, there had been no kaza division administratively in tahrir registers. The lands of Sancak was divided into five nahiyes namely; Birecik, Suruç, Merzuman Ank and Arabon. The number of villages belonging to the nahiyes was 15 in 1523 and 528 in 1584, The numbers of mezras (small villages) which were 217 in 1523, they-totalled 587 in 1584. The people of Birecik Sancağı could be divided into four groups that is, those people living in cities and villages, nomadic people and foreigners. The estimated population of san cak was 31, 446 in 1536 and 70, 290 in 1584. 89.6 % of the Sancak's population were Mus lims in 1536 and the Muslim population were 92 % in 1584. There was no non-muslim in the cities Birecik and Rumkale, and in the nahiyes Birecik and Suruç. The christian population living in the villages of Merzuman, Ank and Araban nahiyes accounted for one - tenth of the total population in 1536, it decreased to 8 % of the total in 1584. The economic structure of Birecik Sancağı was predominantly based on agriculture. The revenues of the Sancak, totalled 2, 105, 212 akças in 1536; 8/10 of which was collected from238 the rural areas while the remaining part was obtained from the urban areas. It is understood that the share of villages in the economic activities showed an increase in 1584. 9/10 of the revenues which totalled 4, 053 782 akças were collected from the rural areas, while the remaining revenues were provided by the urban areas. Agriculture was the activity of those living in the rural areas. Diverse range of crops, fruits and vegetables were raised on the land which was irrigated by the Euphrates. According to tahrir registers, there were 275.000 decares cultivated land in 1584 while the cultivated land was 643.800 decares in 1584. This increase was realized through the employment of nomadic people in the cultivated lands. Pulses and grain were most cultivated crops within the sancak. In line with the size of the lands and the number of villages, the majority of the production was realized in the nahiyes Birecik and Suruç. Apart from the agriculture, the stock- breeding which included the sheep and goat breeding, was another activity in the Sancak. The tax-revenues from the stock- breeding were 27, 305 akçes in 1536; while they were 114, 570 akçes in 1584. Besides, there 114,570 akçes in 1584. Besides, there were some small industrial establishments such as mill, dyeing workshops The lands of Sancak were divided into three groups such as the lands of vakıf, mülk and miri. 8% of the lands were those of vakıf and mülk. The remaining 92% were those of miri lands (public - lands). Revenues of miri lands were classified into has, zeamet and timar. The largest share belonged to the holders of has. The holders of timar ranked second.