The Mobile Guard (Arabic: طليعة متحركة, Tulay'a mutaharikkah) was an elite light cavalry regiment of Rashidun army during the Muslim conquest of Syria, under the command of Khalid ibn Walid. This force was earmarked as a cavalry reserve for use in battle as required. After the decisive victory at the Battle of Ajnadayn in 634 CE, Khalid, from his army of Iraq, which after Ajnadayn numbered about 8000 men, organised a force of 4000 horsemen, which the early historians refer to as The Army of Sharpeners. Khalid kept this force under his personal command.