Arabia Deserta in the context of "Muhammad al-Idrisi"

The word "Saracen" (/ˈsærəsən/ SARR-ə-sən) was commonly used in medieval Europe to refer to a person who lived in or near what the ancient Romans knew as Arabia Petraea and Arabia Deserta. Its original meaning in Greek and Latin is not known with certainty. By the early medieval period, it had come to be associated with the Arabian tribes. Following the rise of Islam, which occurred in Arabia, the word's definition evolved to refer not only to Arabs, but to Muslims as well. It eventually became the standard adjective among European Christians for all people and things from the Muslim world, regardless of whether they were Arab in origin.

The oldest known source mentioning "Saracens" in association with Muslims is the Greek-language Christian tract Doctrina Jacobi, which was compiled in the Byzantine Empire amidst the Muslim conquest of the Levant. The word became particularly widespread in European societies during the Crusades, when it was used by the Roman Catholic Church and by several European Christian political and military figures.

Arabia Petraea (lit. 'Rocky Arabia') was a Roman province from the 2nd century to the 7th century. It was established after the Roman Empire conquered the Nabataean Kingdom in 106 and existed until the Muslim conquest of the Levant in the 630s. Spanning much of the Sinai Peninsula and part of the Levant, it was bordered by Syria to the north, by Judaea (later Syria Palaestina) to the west, and by Egypt to the southwest. To the east and southeast of Arabia Petraea was non-Roman territory that the Romans knew as Arabia Deserta. These two regions, together with a third region in South Arabia that was called Arabia Felix, accounted for the Arabian Peninsula in Roman geography.

Annexed by Trajan (r. 98–117), Arabia Petraea was a key province along the Limes Arabicus, which delineated the Roman Empire's borders throughout the Arabian Desert. It was also the only province in the Near East that the Romans did not gain and subsequently lose during Trajan's reign, unlike Armenia, Assyria, and Mesopotamia. The province's capital city was initially Petra, as it had been under the Nabataeans, but Bosra later served in this capacity. Most of the province's land was a vast desert that was sparsely populated by nomadic Arab tribes, though there were several urban settlements closer to the Jordan River.

The influence of ancient Rome in the Arabian Peninsula took root through extensive commerce between Arabs and Romans, who frequently traded with each other on the incense route and the spice route. The Romans knew of Arabia in three roughly divided regions: Arabia Petraea (lit. 'Rocky Arabia'), Arabia Deserta (lit. 'Deserted Arabia'), and Arabia Felix (lit. 'Fertile Arabia'). Collectively, they were a natural stop on the Roman trade route with India, especially by way of the Red Sea. While the Roman Republic had held territory in the Levant, it was not until the time of the Roman Empire that parts of Arabia proper came under Roman rule.

Arabia Petraea was a Roman province that was established after the Roman conquest of the Nabataean Kingdom in 106, consisting of the Sinai Peninsula and parts of the Southern Levant. Arabia Deserta referred to the uncontrolled and sparsely populated interior of the Arabian Peninsula, namely the vast Arabian Desert, which was inhabited by various Arab tribes. Arabia Felix, referring to South Arabia, was home to many independent Arab kingdoms, which variously traded with or fought wars against the Romans.