It is narrated from Sayyiduna Jabir bin Samurah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The religion will remain established until there have been twelve caliphs from Quraysh; then, before the Hour, many liars (false claimants to prophethood) will appear."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1795