Imam Ali al-Hadi
Imam al Hadi (a.s) became the Imam of his time at the tender age of 6 years. The people were used to the idea of the Imams (a.s) having knowledge from Allah which is not dependent on age as Muhammad al Jawad (a.s) became an Imam at the age of 8 years and so they were not surprised that al Hadi (a.s), his son, could be an Imam at 6 years old.
However, Mutawakil, the Caliph who had killed his father still had hope that he could influence the mind of Imam al-Hadi (a.s) as he was so young. He therefore ordered a teacher who hated Ahlul-Bayt to become the private tutor of the young Imam (a.s) to try and influence his thinking because he was so afraid his intelligence
The teacher that was chosen was called al-Junaydi and who did not like the family of Prophet Muhammad (s.a.w).
One day, after Al-Junaydi started teaching Imam al Hadi (a.s), someone asked him:
‘What about this boy (Imam al-Hadi) whom you teach?’
Al-Junaydi replied angrily, ‘Do you say “this boy” and not “this sheikh”? I ask you by Allah; do you know anyone in Medina more aware in knowledge and literature than me?’ the man said ‘No!’
Al-Junaydi said, ‘I mention some matters of literature and think that I have elaborated upon them, but he (Imam al-Hadi) opens sections of literature where I myself learn from him. People think that I teach him, but, by Allah, I learn from him…’
Imam al Hadi (a.s) lived in Medina, however he was forced to leave it and travel to a military town in Iraq called Sammarrah were he was first imprisoned, then kept under house arrest for the rest of his life.
Because of the Imam's (a.s) nearness to Allah (s.w) and Allah's (s.w) love for him, the Imam (a.s) was able to display many miracles which put fear and respect in the eyes of his enemies, and love in the hearts of their followers. These miracles are not "super-natural" however they are important as it allowed them to confirm their status in front of the people.
A good example of this is the story of the curtains. The Caliph Mutawakil used to sit on a large thrown in a palace and to get to him people had to go through many large and heavy curtains. Mutawakil used to always ask his guards to draw the curtains open when Imam al- Hadi (a.s) would be summoned. However, one day Mutawakil decided that he did not want to give special treatment to the Imam (a.s) and decided to make the Imam open the curtains himself as a way to humiliate the Imam (a.s).
However when the Imam al-Hadi reached the first set of curtains, a wind came and opened it for him, although there were no windows or doors which could let so much air in. This happened to all the curtains as he approached them and it was a sign to Mutawakil and his guards that the Imam (a.s) had a high position with Allah (s.w). Mutawakil's plan had failed and he was left in awe and feeling embarrassed. From then on Mutawakil always asked the guards to open the curtains for him so that the miracle does not happen again.
The evil Caliph Mutawakil who had brought Imam al Hadi (a.s) to Sammarrah and imprisoned him had many enemies, and soon he was killed. In the beginning, the Caliphs who came after him did not interfere too much in the Imam's life and he was therefore able to spread the true Islamic teachings to his students who came to visit him in his home.
Imam al Hadi's (a.s) became very popular among scholars and this made a new Caliph called Al-Mutaz very angry and he made a plan to poison Imam al Hadi's (a.s) food. Imam al-Hadi (a.s) died soon after eating the poisoned food. His funeral was attended only by his son Imam Hassan al Askari (a.s) who led the funeral prayers and arranged his burial, laying him to rest in his house.