The son of Abu Khalid narrates from his father, from Sayyiduna Jabir bin Samurah (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said: "This religion will remain established until twelve caliphs have arisen." Isma'il said: I think my father said: All of them will be ones upon whom the Ummah agrees.
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1836