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,
Abu Sufyan ibn Harb to intercept it. The Muslim contingent failed to intercept the caravan. They arrived after the caravan had already passed by Medina. Abu Sufyan had learned of the Muslims' plan from scouts he had deployed, and in response, sent a crier to Mecca to rally the Quraysh to arms against the Muslims. The Muslims ended up engaging this Meccan army, a force of around 1000 men, at the plains of Badr several days after they had failed to intercept the caravan. This conflict, the Battle of Badr, ultimately resulted in a Muslim victory. The death of most Quraysh leaders in the