Perhaps the earliest reference to ancient Saracen to appear in history was that of the Sarakenoi people, whom lived in the north-western Arabian peninsula. The Sarakenoi people were very distinct from the Arabs, however, over time the term became so applicable to Arab people it even became synonymous the word Muslim.
The Greek Sarakenoi were originally a northern Arabian tribe, as it was mentioned by historic authors, while the Muslim coming from northwest Africa and Spain were mostly referred to as the "Moors." Etymology suggests that the confusion between the terms happened over the long period of the European chronicles, during the time of the Crusades. In earlier Christian writings the word meant "not from Sarah," or "those empty of Sarah," which were both adopted from old biblical Jewish: "Arabs were descendants of Ishmael, Hagar's son. For that the Saracens were also refered to as Ishmaelites and Hagarenes.
In Ptolemy's Geography, written in 2nd century A.D., there appeared a region named "Sarakene" north of Sinai, which was named after Saraka, a town in between Palestine and Egypt. Apart from the Greek Sarakenoi, Ptolemy also mentions of an attack by Saraceni on a Pescennius Niger's army Aegyptus at about 193 C.E.. Although, any information about this army had been omitted from history, or, if they even really existed.
During the first half of the 3rd century, Arabia was occupied by three distinct tribes; the Taeni, which was later identified as the Arab tribe "Tayyi"; the Arabes; and the Saraceni. The Tayyi occupied from an area surrounding the Khaybar Oasis up to Northern Euphrates. Far north of them by Hejaz, were the Saracens.
The Saracens also appear in Hippolytus, the book of laws of countries, as enemies of the Roman empire. It is said that the Saracens presented formidable military capabilities that the Romans called them "the barbaroi."
Roman's Notitia Dignitatum (a unique document of the Roman imperial chanceries) describes Saracens as compromising distinctive units within the Roman army. Romans describe Saracens to be warriors riding equites, or heavy cavalry.
Two other accounts of the Saracen people were present in Historia Augusta and the Byzantine, Ioannes Malalas. The only difference within the two accounts was that Malalas described all the inhabitants of the Syrian desert as Saracens; while Historia Augusta clearly knew of the distinction between the Arab people, and the Saraceni tribe.
There are more accounts of the Saracens found in Christian literature. One of which carried a connotation of people living on the fringes of established cultures, living off by raiding and pillaging small villages and towns; however, more of savages than fearsome warriors.