קרב אל-קאדסייה
Already in the last years of the life of Muhammad, organised raids began attacking the Sassanid and the Byzantine frontiers. Although these expeditions slowed during the consolidation of the Arabian peninsula under the first Caliph Abū Bakr (the Riddah wars), the latter's successor `Umar ibn al-Khattāb turned his attention northwards, initiating the Arab Muslim conquests. After a number of small successes and setbacks, `Umar decided to replace the capable general Khālid ibn al-Walīd with an important member of the Quraysh tribe, and sent a large Arab force towards Iraq (part of the Sassanid Empire) under the control of the famed Companion Sa`d ibn Abī Waqqās. The young Sassanid monarch Yazdgird III (r. 632 - 651 CE) ordered his advisor and chief general Rostam Farrokhzād to block this threat, and the two armies met on the western side of the Euphrates River, at the village of al-Qādisiyyah (southwest of al-Hillah and al-Kūfah in what is today's Iraq). Negotiations between the two sides carried on and Arab delegations that came to the Persian camp demanded that the latter accept Islam or agree to pay the tribute (jizyah). Rostam, having pessimistic premonitions, tried to delay the battle, but when neither side came to an agreement, fighting broke out. Sa`d himself did not participate in the battle, however, as he suffered from a sciatic illness, but he monitored and directed the proceedings from atop a nearby castle at `Udhayb through his deputy Khālid ibn `Urfutah. The first day of Battle ended with Persian advances and the Arab force appeared as though it would succumb to the much larger Sassanid army. In particular, the latter's war elephants terrified the Arab cavalry, and succeeded in creating confusion among the Arab fighters. By the third day of battle, Arab veterans of the Syrian campaign (being conducted nearly simultaneously) arrived on the scene and reinforced the Arab army. In addition, a clever trick – whereby the Arab horses were decorated in costume – succeeded in frightening the Persian elephants. When an Arab warrior succeeded in slaying the lead elephant, the rest fled into the rear, trampling numerous Persian fighters. The Arab Muslims continued to advance their attacks during the night (called the "Night of Clangour"). At dawn of the fourth day, a sandstorm broke out – blowing sand in the Persians' faces. Quickly, the tide turned and the Sassanid centre gave way, particularly with the help of Arab archers. Rostam, who had been commanding his force from that location, sought to flee by swimming across the canal (al-`Atīq), but was caught by an Arab fighter and beheaded. The latter (sometimes recorded as Hilāl ibn `Ullafah) announced the deed, displaying Rostam's head before the fighters, exclaiming: 'By the Lord of the Ka`bah! I have slain Rustam! I am Hilal ibn 'Ullafah' Seeing their respected leader's head dangling before them, the Persian fighters lost nerve and begin to flee, leading to a devastating rout. Most of the Sassanid fighters lost their lives in this melée, with a small number announcing their conversion to Islam.
