The era of the Eighth Imam is once again a period of the prevalence of a congenial condition for the spread of Shiism. The Imam enjoys ample facilities and this era leads to the appointment of the Imam as the vicegerent, or in other words, as the heir apparent to the Caliph.
However, the Imam observed precautionary dissimulation during the time of Harun, that is, he conducted his efforts and made his endeavors, but camouflaged them. For instance, De'bel Khazai the famous Shiite poet - who supports the Imam during his vicegerency, was not trained overnight.
The upbringing of such people as De'bel Khazai, Ibrahim ibn Abbas who is among the eulogizers of Ali ibn Musa Ridha (as), and others, was possible only in a society where the love for the Progeny of Prophet had a precedent. The appointment of Ali ibn Musa Ridha (as) was not celebrated in Medina, Khurasan, Rey and other regions all of a sudden and without any background.
The appointment of Ali ibn Musa Ridha (as) as heir apparent (Wali-e-Ahd), which is a great event, shows that the people's interest and love for the Progeny of the Prophet (S) during the era of Imam Ridha (as) had considerably developed. However, the clashes between Amin and Mamun which led to a five-year Baghdad-Khurasan war, prepared the grounds for Ali ibn Musa Ridha (as) to launch his extensive activities which finally led to his appointment as the heir apparent.
Unfortunately, this trend was severed with the martyrdom of Imam Ridha (as) and a new era began which is a period of misery, hardship and agony for the Progeny of the holy Prophet (as).
In my opinion, the post-Imam Jawad (as) era is the most difficult and worst time for the infallible Imams. This was a political sketch of the lives of the infallible Imams.
As mentioned above, I divided my discussion into two parts: the first part was allotted to the general features, which is concluded here. The second part refers to some examples of the struggles of the infallible Imams. The issues, which are worthy of discussion, are not limited to what I have said. However, I will mention some of the topics so that the interested scholars work on them. Some of these topics are given below.