He is the Imaam, the example, the Mujaahid, the Shaykh of the Hanbalee scholars and greatest of them in his time: Abu Muhammad Al-Hasan Ibn 'Alee Ibn Khalf Al-Barbahaaree  - an ascription to Barbahaar, which were medicines imported from India. 
His Birthplace and Early Life:
The references available do not mention anything about his birth or early life but it appears that he was born and brought up in Baghdaad. This is apparent form his fame amongst its general public, not to mention its scholars. Further, Al-Barabahaaree sat with a group of the companions of the Imaam of Ahl-us-Sunnah wal-Jamaa'ah, Ahmad Ibn Hanbal,(رحمه الله). He studied under them and most of them came from Baghdaad as will be explained. This shows that he grew up in an environment of knowledge and adherence to the Sunnah. This clearly had a great influence on his personality.
His Teachers and His Seeking after Knowledge:
Al-Barbahaaree was pre-eminent in seeking after knowledge and expanded great efforts to attain it. He acquired knowledge from a group of the senior students of Imaam Ahmad Ibn Hanbal, except that unfortunately, the references available to us only state two of them by name and they are:
- Ahmad Ibn Muhammad Ibn-ul-Hajjaaj Ibn 'Abd-il-'Azeez Abu Bakr Al-Marwazee: The exemplary Imaam, scholar and Muhaddith, a student of Imaam Ahmad. He died on the sixth of Jumaadal-Oolaa in the year 275H. 
- Sahl Ibn 'Abdullaah Ibn Yunus At-Tusturee, Abu Muhammad: The Imaam, worshipper and one known for abstemiousness from this world. Many wise sayings are reported from him and many remarkable happenings. He died in Muharram in the year 283H, at the age of about eighty. 
His Knowledge and the Scholars' Praise for Him:
Imaam Al-Barbahaaree, (رحمه الله), was a formidable and imposing Imaam who spoke out with the truth and called to the Sunnah and to the following of narrations. He also had renown and the respect of the ruler. In his gatherings, various circles for the study of hadeeth, the narrations and Fiqh were held. These were attended by many of the scholars of hadeeth and fiqh. 
The scholar, Abu 'Abdullaah said:
"If you see a person of Baghdaad loving Abul-Hasan Ibn Bashshaar and Abu Muhammad Al-Barbahaaree, then know that he is a person of the Sunnah." 
His high status is known by what his student, Ibn Battah,(رحمه الله), said:
"I heard him - meaning Al-Barbahaaree - saying when the people were prevented from Hajj: O People! If anyone needs assistance to the level of a hundred thousand Deenaars and a hundred thousand Deenaars and a hundred thousand Deenaars - five times - then I will assist him." Ibn Battah said: "If he wanted it the people would have given it to him."
As regards the scholars' praise for him, then a great deal has been reported:
Ibn Abee Ya'laa said:
"Shaykh of the Community in his time and the foremost of them in censuring the people of innovation and in opposing them with his hand and tongue. And he had renown with the ruler and prominence amongst those of knowledge. And he was one of the wise scholars, great and precise memorizers of the texts and one of the reliable believers"
Adh-Dhahabee said in Al-'Ibar:
"...the exemplary scholar, Shaykh of the Hanbalees in 'Iraaq in speech, action and sticking to what is lawful. He had great renown and total respect."
Ibn Al-Jawzee said:
"...He gathered knowledge and abstention form this world (zuhd) and was strong against the people of innovation."
Ibn Katheer said:
"The abstemious, man of knowledge, the Hanbalee scholar, the admonisher - and he was strict against the people of innovation and sin. He had great standing and was respected by the elite and by the common people."
His Piety and Abstemiousness:
Imaam Al-Barbahaaree was known for both of these qualities. This can be seen by what Abul-Hasan Ibn Bashshaar mentioned:
"Al-Barbahaaree shunned seventy-thousand Deenaars, which he inherited from his father."
Ibn Abee Ya'laa said:
"Al-Barbahaaree strove greatly and stood form for the Religion many times."
His Position with Regard to the People of Innovation:
Imaam Al-Barbahaaree, (رحمه الله), was very stern against the people of innovations and deviant sects, opposing them with his tongue and his hand, all the while following the way of Ahl-us-Sunnah wal-Jamaa'ah with regards tot he treatment of the people of innovation and deviation. His desire was that this Religion remain pure and be kept free from all that the people of innovation and deviance sought to attach to it, whether the beliefs of the Jahmiyyah, the Mu'tazilah, the 'Ash'arees, the Soofees or the Shee'ah and Raafidees.
He makes clear the methods employed by the people of deviant sects to give sanction to their innovations, and he warns us against falling into their ways and methods. He lays out for us the broad and clear outlines describing the people of deviant sects and innovations. It is as if you are looking straight at them.
In summery, his position with regard to the people of deviant sects and innovations was clearly one of opposition and sternness due to his concern and love for the Sunnah and due to the efforts of every deviant innovator to attack it. His position is rightfully seen as a fine example of the positions of the Imaams of Ahl-us-Sunnah with regard to the people of innovation, deviation and misguidance.
A large number of students learned from this Imaam and benefited from him, since he was an example in both word and deed. And from these students are:
- The exemplary Imaam and Scholar, Abu 'Abdillaah Ibn 'Ubaydullaah Ibn Muhammad Al-'Ukbaree, well known as Ibn Battah, who died in Muharram of the year 387H. 
- The exemplary Imaam, well known for his wise sayings, Muhammad Ibn Ahmad Ibn Isma'eel Al-Baghdaadee, Abul-Husayn Ibn Sam'oon, the admonisher, famous for his deeds and condition. He died in the middle of Dhul-Qa'adah in the year 387H. 
- Ahmad Ibn Kaamil Ibn Khalf Ibn Shajarah, Abu Bakr, the narrator of this book from its author.
- Muhammad Ibn Muhammad Ibn 'Uthmaan, Abu Bakr, about whom Al-Khateeb Al-Baghdaadee (رحمه الله) said: "It reaches me that he used to lead the life of an ascetic and was upon good except that he reported some things that were weak and without basis." 
A Glimpse of His Words and Poetry:
Abu 'Abdillaah Ibn Battah (رحمه الله) said:
"I heard Abu Muhammad Al-Barbahaaree say: 'Sitting in order to advise sincerely is to open the door of benefit and sitting in order to debate is to close the doors of benefit.'" And he said: "The people are in constant delusion."
From his poetry is:
"Whoever satisfies himself with what suffices him -
Begins rich and continues in following the correct way:
How fine an attribute Allaah has made being satisfied with what suffices -
How many a humble person it has raised high
The soul of the youth feels constricted if it he is poor
But if he is patiently depended upon his Lord he would indeed be given ease and sufficiency."
His Trial and Death:
Imaam Al-Barbahaaree, (رحمه الله), had renown and a position of great respect with the common people and the elite and also had status in the eyes of the ruler. However, his enemies from the people of the deviant sects and innovations did not cease in their efforts to incite the ruler against him and to cause anger in his heart against him. This was the point that in the year 321H, the Khaleefah Al-Qaahir ordered his minister Ibn Muqlah to arrest Al-Barbahaaree and his students. Al-Barbahaaree hid, however a group of his major students were captured and taken to Basrah. Allaah, the most High, punished Ibn Muqlah for this action by causing Al-Qaahir Billaah to become angry with him, so Ibn Muqlah fled and was removed from his post and his house burned. Then Al-Qaahir Billaah was himself imprisoned on the sixth of Jumaadal-Aakhirah, 322H. He was stripped of his position and blinded in both eyes. Then Allaah, the Most High, granted that Al-Barbahaaree return to his place of honor.
When Abu 'Abdillaah Ibn 'Arafah, well known as Niftawaih died, his funeral was attended by many prominent people and scholars and the congregation was lead by Al-Barbahaaree and that occurred in Safar of the year 323H. it was in this year also that Al-Barbahaaree's standing grew and his words carried greater weight and his students became apparent and spread amongst the people, censuring the innovators. It reached the point that once when Al-Barbahaaree was on the western side of the city and sneezed, his students replied to him and (were so many that) the Khaleefah heard the noise they made in his apartment, so he asked about what had happened. So when he was informed he became afraid.
The innovators still did not cease trying to cause the heart of the Khaleefah Ar-Raadee to turn against Al-Barbahaaree to the point that Ar-Raadee gave the order to Badr Al-Harasee, his chief of police, that he should ride out in public in Baghdaad with the proclamation that no two students of Al-Barbahaaree were allowed to meet together. Again he hid himself having previously settled in the west of the city he now secretly moved to the east. He died in this state in the year 329H.
Ibn Abee Ya'laa said: Muhammad Ibn Al-Hasan Al-Muqri narrated to me, saying: My grandfather and also my grandmother related to me that:
"Abu Muhammad Al-Barbahaaree was hidden by the sister of Toozoon in the eastern side of the town in the alleyway of the public bathhouse...he was there for about a month then his blood ceased flowing. When Al-Barbahaaree died, still in hiding, the sister of Toozoon said to her servant: 'Find someone to wash him.' So someone came to wash him and the door was kept locked so that no one would know. He alone stood to pray for him, but when the woman who owned the house looked, she found that it was full of men wearing white and green clothing. After he had ended the Funeral Prayer, she did not see anyone at all, so she called to her servant and said: 'You have destroyed me along with my brother!' So he said: 'Did you not see what I saw?' 'Yes', she replied. He said: 'Here are the keys to the door and it is still locked.' So she said: 'Bury him in my house and when I die bury me near him...'"
May Allaah have mercy on Imaam Al-Barbahaaree and grant him a great reward. He was an Imaam in truth, an example, knowing Allaah, and a follower of the Sunnah, and an unsheathed sword against the people of innovation and deviation.
 Sources for his biography include Tabaqaatul-Hanaabilah (2/18-45) of Ibn Abee Ya'laa, Al-Muntazam (14/14-15) of Ibn ul-Jawzee, Al-Kaamil fit-Taareekh (8/378) of Ibn ul-Atheer, Al-'Ibar Fee Khabar man ghabar (2/33) of adh-Dhahabee, Siyar A'laamin-Nubalaa' (15/90-93) of adh-Dhahabee, Taareekh ul-Islaam (pp. 258-260) of adh-Dhahabee, Al-Bidaayah wan-Nihaayah (11/213-214) of Ibn Katheer, Al-Waafee bil Wafayaat (12/146-147) of as-Safadee, Al-Manhaj ul Ahmad (2/26-39) of al-'Aleemee, Al-Maqsad ul-Arshad (1/228-230) of Ibn Muflih and Manaaqib ul-Imaam Ahmad (pp. 512-513) of Ibn ul-Jawzee.
 Refer to al-Ansaab of as-Sam'aanee (1/307) and al-Jubaab of Ibn ul-Atheer (1/333).
 His biography can be found in Taarekh Baghdaad (4/423), Tabaqaat ul-Fuqhahaa' of ash-Sheeraazee (p. 170), Tabaqaat ul-Hanaabilah (1/56) and Siyar A'laamin-Nubalaa' (13/173).
 His biography can be found in al-'Ibr (1/407) and as-Siyar (13/330).
 Tabaqaat ul-Hanaabilah (2/44).
 Tabaqaat ul-Hanaabilah (2/58).
 His biography can be found in al-'Ibr (2/171) and as-Siyar (16/529).
 His biography can be found in al-'Ibr (2/172) and as-Siyar (16/505).
 His biography can be found in Taarekh Baghdaad (3/225) and al-Meezaan (4/28).