Abdallah ibn Ali
... that after the death of the first Abbasid caliph, al-Saffah, his uncle Abdallah ibn Ali led a revolt and tried to claim the throne from al-Saffah's brother, al-Mansur?
... that after the death of the first <a class="mw-redirect" href="./Abbasid" id="mwDZk" rel="mw:WikiLink" title="Abbasid">Abbasid</a> caliph, <a href="./Al-Saffah" id="mwDZo" rel="mw:WikiLink" title="Al-Saffah">al-Saffah</a>, his uncle <b id="mwDZs"><a class="mw-redirect" href="./Abdallah_ibn_Ali" id="mwDZw" rel="mw:WikiLink" title="Abdallah ibn Ali">Abdallah ibn Ali</a></b> led a revolt and tried to claim the throne from al-Saffah's brother, <a href="./Al-Mansur" id="mwDZ0" rel="mw:WikiLink" title="Al-Mansur">al-Mansur</a>?