The Quraysh (Arabic: قريش) were a mercantile Arab tribe that historically inhabited and controlled Mecca and its Ka'aba. The Islamic prophet Muhammad was born into the Banu Hashim clan of the Quraysh tribe. The Quraysh staunchly opposed Muhammad until converting to Islam en masse in 630 AD.
No one was forced to convert to Islam. Abu Sufyan and his son Mo'awiyah and Khalid ibn al-Waleed and others from Quraish saw the victory of Islam, and became sure that there will be no future but under the banner of Islam, they wanted to secure a political and social future for them, by declaring themselves as Muslims. The Prophet never punished them on their long history of fighting against Islam, but told them: Go away, you are been freed اذهبوا فأنتم الطلقاء.
The 12 successors hadith is common between Sunnis and Shiis.Even then the Twelver Shia are the only ones who uniquely have 12 Imams all of them being from Quraysh. This in itself is an important indication.
There are other explicit traditions in the Shii collections in which the Prophet names the 12 Imams. This can be found in Kamal al-Din of Sh. al-Saduq as one such example.
There does not appear to be much in-depth history on the circumstances of these narrations and who transmitted them. By the time that they were narrated in Bukhari and Muslim the concept of 'Imam' did exist explicitly and was known in wider circles. It certainly would not have been in the interests of Bukhari to cite a narration that mentioned the word 'Imam' and 'Bani Hashim', since that would have clearly overturned the forced legitimacy of Abu Bakr and 'Umar's caliphates. In particular 'Umar held that that the successorship belonged to 'the people' (meaning Quraysh). The Uthmaniyya, being of Quraysh, therefore held that the caliphate belonged to them. One can surmise that perhaps there may have been narrations in circulation predicting twelve Imams, but that the wording had been 'adjusted' to mask the true implication, if not to 'redirect' the meaning of the narration to suit political purposes. It really needs an expert like Suleiman Ali Mourad (who has analysed the 'transferral of authorship' between the Ahl al-Bayt (as) and various figures in the Sufi tradition, i.e. the attribution to Sufi figures of sayings of the Ahl al-Bayt) to do a proper textual, historical analysis of these narrations.
The treaty of Hudaibiyyah aimed to save Muslims from the harm of the Infidels of Quraish. Fighting with the Infidels of Quraish at that time and situation was not useful at all for Muslims, that is why the Prophet (SAWA) made that treaty to safeguard the interest of Islam and Muslims.
The Treaty of Hudaybiyyah is very important event in the history of early Islam. After the signing of the treaty, the Quraysh of Mecca no longer considered Muhammad to be a rebel or a fugitive from Mecca. It also allowed the Muslims who were still in Makkah to practice Islam freely. In addition, the Treaty of Hudaybiyyah paved the way for many other tribes to make treaties with the Muslims and many Arab tribes to become near to Islam and ultimately become Muslims.
In Sunni books as well as Shia books, it is narrated that The Prophet Muhammad (SAWA) has clearly said: My successors will be twelve , all of them from Bani Hashim.
This is one of Sunni very important books which narrated this Hadeeth:
Yanabee' Al-Mawaddah by Al-Qundoozi Al-Hanafi, Vol 3, Page 445.
The narration of Quraysh is the ne which has been publicized by those who dont want to mention Ahlul Bayt (AS).