The Rashidun army (Arabic: ) was the core of the Rashidun Caliphate's armed forces during the early Muslim conquests in the 7th century. The army is reported to have maintained a high level of discipline, strategic prowess and organization, granting them successive victories in their various campaigns.In its time, the Rashidun army was a very powerful and effective force. The three most successful generals of the army were Khalid ibn al-Walid, who conquered Persian Mesopotamia and the Roman Levant, Abu Ubaidah ibn al-Jarrah, who also conquered parts of the Roman Levant, and Amr ibn al-As, who conquered Roman Egypt. The army was a key component in the Rashidun Caliphate's territorial expansion and served as a medium for the early spread of Islam into the territories it conquered.

The Battle of Dathin (Arabic: داثن) was a battle during the Arab–Byzantine Wars between the Rashidun Caliphate and the Byzantine Empire in February 634, but became very famous in the literature of the period.The battle took place following a series of Arab raids around Gaza. The Byzantine commander (dux and candidatus) Sergius assembled a small detachment of soldiers (due to a shortage of troops), and led that mounted army from his base at Caesarea some 125 kilometers south to the vicinity of Gaza. From there he proceeded against an Arab force that was numerically superior and commanded by 'Amr ibn al-'As. The opposing forces met at the village of Dathin on February 4, not far from Gaza. The Byzantines were defeated and the candidatus Sergius himself was killed, together with 300 of his soldiers. The battle also claimed the lives of 4,000 civilians.

According to the near-contemporary Doctrina Jacobi nuper baptizati, the Muslim victory was celebrated by the local Jews, who had been a persecuted minority within the Roman Empire.