The First Civil War in Islam
As soon as the news of the death of Muhammad Mustafa spread beyond the environs of Medina, false Prophets appeared in many parts of the country. More well-known among them were Musailama in Yamama; Tulaiha Asadi in Nejd; Laqait bin Malik in Oman; and Aswad Ansi in Yemen. Some of them wanted the government of Medina to share its authority with them, and some others wanted "autonomy" in their territories. Abu Bakr sent his troops against them which suppressed them.
Usama's Expedition
As noted earlier, the Prophet had organized, from his deathbed, a new army to attack Syria. He had appointed Usama, a lad of 18, as the general of this army, and he had placed all his companions under his command. His orders to this army were to leave Medina immediately. But the companions did not want to leave Medina, and they did not - until the Prophet died.
But after the death of the Prophet, when Abu Bakr felt secure in the seat of power, he showed great promptness in sending Usama's army to Syria. He said that one thing that he could not do, was to countermand the orders of his late master.
Abu Bakr walked with Usama's army for some distance to acquire "merits" for himself. When he thought he had acquired enough merits, he sought the General's permission to return to the city. He also requested the General to allow Umar to stay with him (with Abu Bakr) in Medina since he would need his advice in running the government.
Usama granted both requests and Abu Bakr and Umar returned to Medina.
At length Usama left Medina and marched toward the north at the head of his army minus Abu Bakr and Umar. But his army had lost its élan. He now perhaps did not know what to do, and returned to Medina after an absence of two months.
source : www.sibtayn.com
