The occultation of His Eminence, the Master of the age (a.s) is a necessary thing and His Eminence is not needless of it. We shall discuss those factors that rendered it an absolute necessity.
1. Fear of tyrannical Abbaside regime
When Abbaside rulers gained power they initiated the worst of atrocities and tortures on the Holy Imams (a.s). Basically they considered the school of Ahle Bayt (a.s) and anyone who was their adherents to be eligible for extreme pressure and restrictions. They were thrown into horrible prisons and then put to death. Poets and historians have drawn a pathetic picture of the perilous circumstances suffered by the Alawite Sayyids.
Abu Ataa says:
Alas! If only the oppression of the Merwanids (Bani Umayyah) had returned and the justice of Abbasides were destroyed and thrown into the fire.
Dibil Khuzai says:
The oppression of Bani Abbas has covered everything and no one was secure from its oppression. If we regard the oppression of Bani Umayyah an expected fact, as they were enemies of Bani Hashim, how can we justify the oppression of Bani Abbas who were themselves from Bani Hashim