through either cultural assimilation (partial/incomplete Arabization within certain communities), or as a pan-ethnic identity, as well as partially Arabized communities. }} The Arabs (singular: Arab; singular , DIN 31635: , , plural , DIN 31635: , Arabic pronunciation: ), also known as the Arab people, are an ethnic group mainly inhabiting the Arab world in Western Asia and North Africa, and to a lesser extent the Horn of Africa, and the western Indian Ocean islands (including the Comoros). An Arab diaspora is also present around the world in significant numbers, most notably in the Americas, Western Europe, Turkey, Indonesia, and Iran. In modern usage, the term "Arab" tends to refer to those from Arab nations, who both carry that ethnic identity and speak Arabic as their native language. This contrasts with the narrower traditional definition, which refers to the descendants of the tribes of Arabia. The religion of Islam was developed in Arabia, and Classical Arabic serves as the language of Islamic and Arabic literature. 93 percent of Arabs are Muslims (the remainder consisted mostly of Arab Christians), while Arab Muslims are only 20 percent of the global Muslim population. The first mention of Arabs appeared in the mid-9th century BCE, as a tribal people in eastern and southern Syria and the northern Arabian Peninsula. The Arabs appear to have been under the vassalage of the Neo-Assyrian Empire, as well as the succeeding Neo-Babylonian, Achaemenid, Seleucid, and Parthian empires. The Nabataeans, an Arab people, established a kingdom centered in Petra (modern-day Jordan) in the 3rd century BCE. Arab tribes, most notably the Ghassanids and the Lakhmids, began to appear in the southern Syrian Desert from the mid-3rd century CE onward, during the middle to later stages of the Roman and Sassanid empires. Before the expansion of the Rashidun Caliphate, the term "Arab" referred to any of the both largely nomadic and settled Arabic-speaking people from the Arabian Peninsula, the Syrian Desert, and Lower Mesopotamia, with some even reaching what is now northern Iraq. Since the height of pan-Arabism in the 1950s and 1960s, "Arabs" has been taken to refer to a large number of people whose native regions became part of the Arab world due to the spread of Islam, which saw the expansion of Arab tribes and the Arabic language throughout during the early Muslim conquests of the 7th and 8th centuries. These cultural and demographic influences resulted in