The Battle of Al-Qadisiyah is one of the largest Islamic battles that took place between the Persians and the Muslims that took place on the thirteenth of Shaban in the year 15 AH. The leader of the Muslims at the time was our master Saad bin Abi Waqas, may God be pleased with him, and the leader of the Persians was Rustam Farrokhzad. The battle ended with victory for the Muslims, and it was the most important Islamic battle in the conquest of Iraq.

During the lifetime of the Messenger, may God’s prayers and peace be upon him, Persia was ruled by Khosrau II, who waged war on the Byzantine Empire in order to avenge the killing of Emperor Maurice and the Sasanian army seized Anatolia, the Levant and Egypt, and in 610 AD Heraclius assumed Byzantine rule and led them to war in order to recover the land and succeeded in restoring the land Among them, the army of Persia was defeated in the Battle of Nineveh, and one of Khosra's son turned against him, Qubad the second, and ordered the execution of his father and all of his brothers, including Mardan Shah, the favorite son of Kusra and heir to the throne.

And he began with peace with the Romans and the restoration of all the lands occupied by the Persians, and after that the internal conflict occurred in Persia, so Khosrau II was killed by his son in 628 AD, and his brothers were executed and he began negotiations with Hercules and after a few months of rule, he was afflicted with the plague disease and the civil war began to appear, and his son was appointed Ardashir III was king, at the age of seven years, and was killed after only 18 months by General Shahr Baraz, who seized Jerusalem and Damascus.

He was killed in 629 AD and was succeeded by the daughter of Khosrau II Burandakht and tried to achieve justice, and after five years of internal conflict in the Persian house, Yazdegerd III, the grandson of Khosrau, took over at the age of eight, and Firuz Khusraw was one of the pillars of his state and was known as Al-Firdan.
After the death of the Prophet, may God bless him and grant him peace, and Abu Bakr Al-Siddiq assumed the caliphate after him, he began to continue the invasions after the wars of apostasy, so he launched campaigns against the Levant until the Islamic state clashed with the Persian and Roman Empire.

Al-Siddiq, may God be pleased with him, ordered Khalid bin Al-Walid, may God be pleased with him, to go to southern Iraq to call them to Islam. So our master Khalid directed the army, and when he reached the Hafir area, the Persian commander Hormuz confronted him, and a battle took place near Kazma between the Persians and the Muslims.

After that, the defeats of the Persians continued and the Muslims became on the verge of Al-Hirah, so its rulers felt fear of the coming of the Muslims and took care of the matter, and the Muslims put in place a tight military plan. Al-Hirah is the base of the Islamic Army, and after the situation settled, he headed to Anbar and Ain Al-Tamr and conquered it.

After a period of Dumat al-Jandal rebellion, so our master Khalid went to her, so the Christian Arabs living on the Euphrates shore declared rebellion, and when he returned to Al-Hirah, he eliminated the unrest until Abu Bakr ordered him to go to the Levant, and took command of the Islamic army in the land of Iraq. The capabilities of the Islamic Army are insufficient to confront the Persians due to the unification of their home front.

And when our master Omar bin Al-Khattab assumed the caliphate after the death of Al-Siddiq, may God be pleased with them, he urged people to go out to jihad in the land of Iraq, and Muthanna drew up his military measures and camped with soldiers in southern Iraq awaiting the arrival of Abu Ubaid al-Thaqafi in terms of access from Medina.
When he arrived, the Battle of the Nimariks took place and the defeats of the Persians followed afterwards until the Euphrates River became between the Muslims and the Persians, and the Persians brought elephants in the battle, and the Muslims crossed the river and met with the Persians in the Battle of Al-Buwab.