Al-Ubeidiya is named after Saint Theodosius, who built and was buried in a monastery west of the town, known as the Monastery of St. Theodosius. It was originally constructed in the 5th-century CE and Theodosius was buried there in 529. The current structure was built by the Crusaders in the 12th-century. It is located on a hilltop and is under the administration of the Greek Orthodox Church. The Mar Saba Monastery—which was built by Saint Sabbas in 484 CE—is located further east of the town center, but within its municipal jurisdiction. An Ancient Roman pool is situated in the center of al-Ubeidiya and was used in the Roman era of rule in Palestine to collect water. According to Dauphin, most of current the Monastery dates from the 19th century, but incorporates Byzantine remains.
Ottoman era
The area, like the rest of Palestine, was incorporated into the Ottoman Empire in 1517. In 1596 Al-Ubeidiya appeared in Ottoman tax registers, called Dayr Bani 'Ubayd, being in the nahiya of Al-Quds in the liwa of Al-Quds. It had a population of 42 households and 6 bachelors, all Muslim. They paid a fixed tax-rate of 33,3 % on agricultural products, including wheat, barley, occasional revenues, goats and/or beehives; a total of 4,900 akçe. According to local tradition, the modern town of al-Ubeidiya was founded when members of the Shammar tribe from the Arabian Peninsula settled there, and it was not named after St. Theodosius, but after tribal leader, al-Ubeidi Faris. Around 1740 Richard Pococke noted "We soon came to a ruin called Der Benalbede, which from the name seems to have been an old convent." In 1838, Edward Robinson noted Deir ibn Obeid, not far from Mar Saba, on his travels in the region. He also met some of the fellahin from the village by the Dead Sea, where they collected salt for cooking. In 1863, the French explorerVictor Guérin visited the place, which he called Deir Dosi, and described the remains of the monastery. In 1883, the PEF's "Survey of Western Palestine" described there Kh. Deir Ibn Obeid as "Ruins of a modern village", but in 1899 Conrad Schick noted that "This designation is not sufficient -the ruins are not those of a village, but of a former convent, and only in the modern times used as a storehouse for grain for the wandering tribe Ubedieh."
In the 1922 census of Palestine, conducted by the British Mandate authorities, the tribal area of Ibaidiyeh had an all Muslim population of 2,000, 880 males and 1,120 females. In the 1931 census the El Ubeidiya consisted of 1,187 persons, still all Muslim, 610 males and 577 females. In the 1945 statistics the population was counted under the name of tribal unit Arab Ibn Ubeid, together with Arab et Ta'amira, Arab et Rashayida and Arab et Sawahira; together they had a population of 7,070 Muslims,, where Arab Ibn Ubeid had a total of 92,026 dunams of land according to an official land and population survey. Of this, 3,732 dunams were used for cereals, while 88,294 dunams were classified as non-cultitivable land.
Since the Six-Day War in 1967, al-Ubeidiya has been under Israeli occupation. The population in the 1967 census conducted by the Israeli authorities was 1,377. After 1995, 9.1% of village land is defined as Area A land, 0.4% as Area B, and the remainder 82% as Area C. Israel has confiscated land from Al-Ubeidiya in order to construct Israeli settlements; 124 dunams were taken for the construction Avenat, while 97 dunams were taken for ‘Ayn Fashkhah. Since 1997, al-Ubeidiya has been governed by an 11-member municipal council appointed by the Palestinian National Authority. The municipality has jurisdiction over 97,232 dunams of land—much larger than the built-up and residential areas of the town which constitute 979 of those dunams. Other localities located within the municipal borders include Wadi al-Arayis. The residents are mostly descendants of the Shammar with the main families being al-'Asa, al-Radayda, al-Rabai'a, al-Hasasna, and Abu Sirhan. The population is Muslim and there are ten mosques in the town.
