Muhammad's wife Khadijah and his uncle Abu Talib both died in 619, the year thus being known as the "year of sorrow". With the death of Abu Talib, the leadership of the Banu Hashim clan was passed to Abu Lahab, an inveterate enemy of Muhammad. Soon afterwards, Abu Lahab withdrew the clan's protection from Muhammad. This placed Muhammad in danger of death since the withdrawal of clan protection implied that the blood revenge for his killing would not be exacted. Muhammad then visited Ta'if, another important city in Arabia, and tried to find a protector for himself there, but his effort failed and further brought him into physical danger. Muhammad was forced to return to Mecca. A Meccan man named Mut'im b. Adi (and the protection of the tribe of Banu Nawfal) made it possible for him safely to re-enter his native city.
Many people were visiting Mecca on business or as pilgrims to the Kaaba. Muhammad took this opportunity to look for a new home for himself and his followers. After several unsuccessful negotiations, he found hope with some men from Yathrib (later called Medina). The Arab population of Yathrib were familiar with monotheism and prepared for the appearance of a prophet because a Jewish community existed there. They also hoped by the means of Muhammad and the new faith to gain supremacy over Mecca, as they were jealous of its importance as the place of pilgrimage. Converts to Islam came from nearly all Arab tribes in Medina, such that by June of the subsequent year there were seventy-five Muslims coming to Mecca for pilgrimage and to meet Muhammad. Meeting him secretly by night, the group made what was known as the "Second Pledge of al-`Aqaba", or the "Pledge of War" Following the pledges at Aqabah, Muhammad encouraged his followers to emigrate to Yathrib. As with the migration to Abyssinia, the Quraysh attempted to stop the emigration. However, almost all Muslims managed to leave
