Qalqilya or Qalqiliya (Qalqīlyaḧ) is a Palestinian city in the West Bank which serves as the administrative center of the Qalqilya Governorate of the State of Palestine. In the 2007 census, the city had a population of 41,739. Qalqilya is surrounded by the Israeli West Bank wall, with a narrow gap in the east controlled by the Israeli military and a tunnel to the Palestinian town of Hableh. Qalqilya is under the administration of the Palestinian National Authority (as part of Area A), while remaining under Israeli military occupation. Oranges are a major part of the city's economy. Qalqilya was known as Calecailes in the Roman period, and Calcelie in the Frankish sources from the early Medieval times. The word "Qalqilya" might be derived from a Canaanite term which means "rounded stones or hills".According to E.H. Palmer, the name came from "a type of pomegranate", or "gurgling of water". The vicinity of Qalqilya has been populated since prehistoric times, as attested to by the discovery of prehistoric flint tools. In 1596, Qalqilya appeared in Ottoman tax registers (transliterated as Qalqili) as a village in the nahiya (subdistrict) of Bani Sa'b in the Liwa of Nablus. It had a population of 13 Muslim households and paid a total of 3,910 akçe in taxes on wheat, barley, summer crops, olives, and goats or beehives. In 1838, Edward Robinson noted Kulakilieh as a village in Beni Sa'ab district, west of Nablus. In 1870, Victor Guérin said it was a village with 200 inhabitants. In 1882, Qalqilya was described as "A large somewhat straggling village, with cisterns to the north and a pool on the south-west. The houses are badly built." In 1883 some moved there from nearby Baqat al-Hatab, and in 1909 a municipal council to administer Qalqilya was established. In the 1922 census of Palestine conducted by the British Mandate authorities, Qalqilya had a population of 2,803 (2,794 Muslims and 9 Christians), increasing in the 1931 census to 3,867 (3,855 Muslims and 12 Christians), in a total of 796 houses.