Islam migrants ("Muhajirun"), Muhammad in Medina established his political and religious authority. The Constitution of Medina was formulated, instituting a number of rights and responsibilities for the Muslim, Jewish, Christian and pagan communities of Medina, bringing them within the fold of one community—the Ummah. The Constitution established: All the tribes signed the agreement to defend Medina from all external threats and to live in harmony amongst themselves. Within a few years, two battles took place against the Meccan forces: first, the Battle of Badr in 624 – a Muslim victory, and then a year later, when the Meccans returned to Medina,
Battle of the Bridge Battle of the Bridge The Battle of the Bridge or the Battle of al-Jisr () was a battle at the bank of the Euphrates river between Arab Muslims led by Abu Ubaid al-Thaqafi, and the Persian Sasanian forces led by Bahman Jaduya. It is traditionally dated to the year 634, and was the only major Sassanian victory over the invading Muslim armies. The Muslim forces had already taken Hira and assumed control of the surrounding Arab-inhabited areas of Mesopotamia, on the banks of the Euphrates. The fall of Hira shocked the Persians, as the "youthful Yazdgard, began to take the