In 1179 the village (named Casale Age) was mentioned together with Fahma in Crusader sources as being among the villages whose revenue were given to the Zion Abbey by Pope Alexander III.[4][6]
Ottoman era
Ajjah, like the rest of Palestine, was incorporated into the Ottoman Empire in 1517, and in the census of 1596 it was a part of the nahiya ("subdistrict") of Jabal Sami which was under the administration of the liwa ("district") of Nablus. The village had a population of 13 households, all Muslim. The villagers paid a fixed tax-rate of 33,3% on agricultural products, such as wheat, barley, summer crops, olive trees, beehives and/or goats, in addition to occasional revenues, a tax for people of liwa Nablus, and a press for olive oil or grape syrup; a total of 3,612 akçe.[7] Pottery sherds from the Ottoman era have also been found here.[4]En-Nabulsi (1641 – 1731), noted Ajjah as "a village on the road from Fahme and er-Rameh".[4]
In 1830, the people of Ajjah fought against the army of Emir Bashir Shihab II during the siege of Sanur.[4] In 1838, 'Ajjeh was noted as being in the District of esh-Sha'rawiyeh esh-Shurkiyeh, the eastern part.[8][9]
In 1870, Victor Guérin noted it as a village on a hill, covering its summit, with 500 inhabitants, surrounded by olive groves.[10] In 1871 (1288 AH), an Ottoman census listed the village in the nahiya (sub-district) of al-Sha'rawiyya al-Sharqiyya.[11]
In 1882, the PEF's Survey of Western Palestine described Ajjeh as: "A village of small size, but of ancient appearance, perched on the edge of a hill, and built of stone, with olive groves below. It has a cistern on the south-east."[12]
In the 1944/5 statistics the population of Ajja was 890 Muslims,[15] with a total of 11,027 dunams of land, according to an official land and population survey.[16] Of this, 737 dunams were used for plantations and irrigable land, 5,605 dunams for cereals,[17] while 23 dunams were built-up (urban) land.[18]
The Jordanian census of 1961 found 1,190 inhabitants.[19]
Post-1967
Since the 1967 Six-Day War, Ajjah has been under Israeli occupation. In 1978, the Medieval fortress still crowned the summit of the village, and around it were buildings from the 16th and 17th CE, and two mosques.[20]
^Government of Palestine, Department of Statistics, 1945, p. 16Archived 2018-09-05 at the Wayback Machine
^Government of Palestine, Department of Statistics. Village Statistics, April, 1945. Quoted in Hadawi, 1970, p. 54Archived 2012-02-29 at the Wayback Machine
^Government of Palestine, Department of Statistics. Village Statistics, April, 1945. Quoted in Hadawi, 1970, p. 98Archived 2014-01-04 at the Wayback Machine
^Government of Palestine, Department of Statistics. Village Statistics, April, 1945. Quoted in Hadawi, 1970, p. 148Archived 2014-01-04 at the Wayback Machine
^Government of Jordan, Department of Statistics, 1964, p. 25
^Grossman, D. (1986). "Oscillations in the Rural Settlement of Samaria and Judaea in the Ottoman Period". in Shomron studies. Dar, S., Safrai, S., (eds). Tel Aviv: Hakibbutz Hameuchad Publishing House. p. 351