Assalmu Alaikum,
Insha'Allah I'll try and provide as many excerpts as possible
from the book Speaking Among Friends. I found this to be very
illuminating.
"In the recent past publications have been consistently circulated attempting to present to the public a biased picture of the Dawoodi Bohra (DB) community which is even blasphemous and derogatory to their religious organization and their revered religious leader, His Holiness Dr. Syedna Taher Saifuddin Saheb, the 51st Dai-el-Mutlaq.
To correct the mischievous consequences of such publications we deem it our religious duty to propagate facts about the community and its institutions. With that objective this concise booklet is presented.
The DB community traces its spiritual heritage from Prophet Mohammed and his Vasi Amirul Mu'mineen Moulana Ali, son-in-law of the Prophet, and continuing through their successors, the Imams, who, functioning first from Medina, spread over to North Africa and Egypt in the succeeding centuries.
Imam Al-Mehdi Billah set out for North Africa and established his religious kingdom in Tunisia and the adjacent territories. He was succeeded by three Imams and the fourth, the celebrated Imam Al-Moiz Ledinillah, established his seat of authority in Egypt.
The great kingdoms these Imams founded, the noble traditions of thought and philosophy they fostered, the immense wealth of literature they produced and guarded, the resplendent civilization they established and the wise way of life they pursued have all come to be called Fatimi after Fatima, the daugher of Prophet Mohammed and the consort of Imam Ali, thus linking two venerable personalities together.
The Fatimi Imams, reigning in glory in Egypt, founded the City of Cairo, started the renowned center of learning, Al Azhar University, which is the oldest institution of its kind in the world to exist to this day, and wrote into Egyptian history the unforgettable Fatimi era. This period and its unrivalled efflorescence of thought, art and culture owe everything to the Fatimi Imamas who were inspired leaders, great builders and lofty thinkers, eminent scholars and writers.
From Egypt the center of Fatimi authority and activity shifted to Yemen in Arabia. When the 20th Imam decided that the time had again come to keep away from the public eye, he made elaborate preparations for enabling his successor to go into seclusion at the appropriate moment and also for the preservations and continuation of the Fatimi tradition, from a congenial new center in neighboring Yemen, and on a new basis..."
Abde Syedna (TUS)
Wa'salaam,
Huzefa