Imams of Shi'a are twelve people from the progeny of the Prophet (s) who are intellectual, spiritual and political leaders of Shi'a. The first one of whom was Imam 'Ali (a) and the rest are Imam 'Ali (a) and Lady Fatima's (a) children and grandchildren. According to Shi'a beliefs, after the Prophet (s), leadership of the Islamic society would always be upon Imams (a) who have been appointed by God. These Imams (a) have God-given knowledge, infallibility and the rights of intercession and by making Tawassul to them, one can become close to God. In addition to authority in religious teachings, these twelve Imams (a) have political leadership of the society as well. There are many hadiths from the Prophet (s) which have described their attributes and mentioned their names and show that all of them are from Quraysh and among the Ahl al-Bayt (a) of the Prophet (s) and the Promised Mahdi (a) is the last one of them. There are clear hadiths from the Prophet (s) about imamate of Imam 'Ali (a), the first Imam. Also, there are definite hadiths from the Prophet (s) and Imam 'Ali (a) about the imamate of the second Imam and respectively Imams (a) have clearly mentioned the Imams after them.[39] According to these hadiths, Imams (a) are 12 and their names are: 'Ali b. Abi Talib (a) Hasan b. 'Ali (a) Husayn b. 'Ali (a) 'Ali b. Husayn (a) Muhammad b. 'Ali (a) Ja'far b. Muhammad (a) Musa b. Ja'far (a) 'Ali b. Musa (a) Muhammad b. 'Ali (a) 'Ali b. Muhammad (a) Hasan b. 'Ali (a) Mahdi (a)