When Abu Bakr, may Allah be pleased with him, became the Caliph in 632 CE, the Islamic State was threatened with disunity and chaos. Within a year, Abu Bakr, may Allah be pleased with him, was strong enough to attack the Persian Empire in the north-east and the Byzantine Empire in the north-west. There were legitimate purposes for this conquest

 

Hormuz was an intolerable man. He was disliked by the 'Iraqis who used to say of him: "There is no infidel more wicked than Hormuz." Yet, in Persia he was regarded as a nobleman of the highest rank.

Getting no reply, Khaalid divided his army into three regiments of 6,000 men each. The first day Muthannaa marched to Hafeer; the second day 'Adiyy bin Haatim, may Allah be pleased with him, followed; and the third day Khaalid found Hormuz occupying the water springs.

Hormuz wanted to cut the fight short by murdering Khaalid treacherously. As soon as the two armies engaged in battle, he challenged Khaalid to fight a duel. Khaalid at once dismounted and before long, his opponent was killed and Khaalid cut off his head and held it by the forelock. The Persians dashed up at full gallop to prevent their captain's death, but the Muslims were ready for them. The Persians took to their heels and a massacre followed. Among the spoils sent to Al-Madeenah were Hormuz's beret and an elephant. The huge animal was publicly admired by old and young, and then returned to 'Iraq to be made use of in the forthcoming campaign. This battle was called “The Battle of the Chains” and it was one of the most important battles, because of its effect on the morale of the Muslim troops. Muslim forces gave blow after blow to the Persian armies. Many places such as Al-Heerah, Al-Anbaar, 'Ayn At-Tamr, and Dawmat Al-Jandal surrendered to the Muslims.

Conquest of the Roman Empire

The marvellous victories of Khaalid bin Al-Waleed, may Allah be pleased with him, in `Iraq encouraged Abu Bakr, may Allah be pleased with him, to send armies to conquer Syria. Abu Bakr sent Khaalid bin Sa'eed, may Allah be pleased with him, at the head of an army to Tayma', just near the Syrian border, but he did not intend to invade the country; it was only a defensive measure. However, when he received letters from Khaalid bin Sa'eed, who longed for military glory in Syria as great as that of Khaalid bin Al-Waleed in `Iraq, asking for permission to proceed, he agreed and gave the signal which started a new campaign. In his first engagement with the Romans, Khaalid bin Sa'eed managed to win the battle and occupy the Roman camps. Tasting victory against "the people of yellow complexion", as they were usually described by the Arabs, Khaalid pushed forward till he reached the shores of the Dead Sea, where he defeated another Roman regiment near Qastal.

Now, the Romans realized that the Muslims were not merely indulging in temporary raids as they used to do before, but that they intended to conquer and stay. So, they sent a huge army led by Bahan, who was well known for his clever military tactics. He withdrew intentionally before Khaalid, who forgot Abu Bakr's piece of advice to be always wary in his war with the Romans. Bahan's retreat stopped when he was in the vicinity of Tiberias. There he managed to trap the Muslims and kill Khaalid's son, Sa'eed, who was lagging behind with a group of his men.

 

The circumstances, which befell Ibn Sa'eed, did not make Abu Bakr despair. He ordered the recruitment of new troops and immediately sent aid to 'Ikrimah, may Allah be pleased with him, who was waiting near the Roman border. The total aid which `Ikrimah received amounted to 30,000 men. `Amr bin Al-'Aas had to proceed to Palestine, Abu `Ubaydah bin Al-Jarraah to Damascus, Sharhabeel bin Hasnah to Jordan and Yazeed bin Abu Sufyaan to Basrah.

When Heraclius, the Roman emperor, heard the news, he mustered about 240,000 troops. Theodore, his brother, led the huge army and proceeded to Waqusah, some 40 miles to the south of Yarmook, a tributary of the Jordan. He camped beside the left bank of the river on a spacious plateau which was surrounded on three sides by high mountains.

 

Then he called ’Umar and advised him on how to lead his people, ending with these words: "If you follow my advice, nothing unknown will be more acceptable to you than death; but if you reject it, nothing unknown will be more frightening than death." Before he died, Abu Bakr, may Allah be pleased with him, gave back everything he had taken from the public treasury during his Caliphate. It is said that he did not bequeath any money at all. He left only a servant, a camel and a garment. His orders were that after his death the garment should be delivered to his successor. On seeing it ‘Umar wept and said: "Abu Bakr has made the task of his successor very difficult."