الخليفة الأول عبيد الله المهدي الفاطمي و علاقته بإسماعيلية اليمن (322-280 ه 894-934 م)‎

الملخص EN

The researcher tries to expose the subject without prejudice or fanaticism, relying on the original sources that were close to the period of study.

The research follows both the experimental and historical approaches without being restricted to the historical sequence, considering into account that this does not come out of the study period.

The research includes three axes: First: Imams of Ismaili before Obeid Allah Al-Mahdi and their interest in the province of Yemen.

Second: The Ismaili Imam Obeid Allah Mahdi and his relationship with the Ismailia of Yemen.

Third: The first Fatimid Caliph Obaid Allah Al-Mahdi and his relationship with Ismailia of Yemen.

The research reveals many results, and depends on many Arabic and foreign manuscripts, sources, and references.