The most published photograph of Aman Abdurrahman is one that shows him behind bars, raising his handcuffed arms, acknowledging his followers with a smile.
That was in 2010, while he was in court facing terrorism charges. Aman has been in jail ever since.
Being imprisoned, however, has not stopped the Islamic cleric from spreading takfiri, a doctrine that denounces all who do not agree with its extremist skew as apostates.
It has also been proven, often with deadly effect, that Aman is able to order attacks on civilian and police targets across Indonesia, as well as recruit, train and deploy his followers to join the Islamic State in Iraq and Syria (ISIS) militant group.
The Indonesian police say three of his four most prominent followers - Bahrumsyah, Muhammad, Bahrun Naim and Salim Mubarak Attamimi alias Abu Jandal - are now in Syria, leading separate groups of militants from South-east Asia fighting for ISIS. The fourth is Santoso, the country's most wanted terrorist.
A year after he was given remission and released in 2008, Aman partnered with Abu Bakar Bashir to set up a JI paramilitary training camp in Aceh. The police raided the camp in 2009 and both men were jailed again. It was during Aman's second time in prison that his influence expanded, inevitably undermining the authority of Bashir, said a government source who asked not to be named.
The police have now added the "Jakarta Four", all followers of Aman who carried out the Jan 14 attacks under his orders, to his gang of loyalists. The list also includes the majority of 19 other suspects detained in the aftermath of the strike.
Besides the siege on Jakarta, police also believe he is linked to several other terror plots, including a suicide bombing at a mosque in Cirebon, West Java, in 2011 and the murder of several police officers in Banten province in 2013.
Born in Sumedang, a town in West Java, Aman, now 44, did well in the madrasahs where he grew up. He also graduated at the top of his class at the Institute of Arabic and Islamic Science in Jakarta and became a preacher and lecturer.
It is not known when he was radicalised but it was in 2003 that he founded the takfiri-centric Tauhid Wal Jihad militant cell in Indonesia.
This was just two years after Jordanian militant Abu Musab al-Zarqawi, who had strong ties to Osama bin Laden and once led Al-Qaeda in Iraq, introduced takfiri in modern times. Zarqawi is also the predecessor of Abu Bakr al-Baghdadi, the leader of ISIS.
Aman has never fought in a battlefield, although he was jailed in 2004 for a failed bombing in Depok, West Java.
But it was during his time in prison when he met Abu Bakar Bashir, then spiritual leader of the now disbanded Jemaah Islamiah (JI) terror network, prison records show.
A year after he was given remission and released in 2008, Aman partnered with Bashir to set up a JI paramilitary training camp in Aceh. The police raided the camp in 2009 and both men were jailed again.
It was during Aman's second time in prison that his influence expanded, inevitably undermining the authority of Bashir, said a government source who asked not to be named.
The brand of violence based on takfiri that Aman preached attracted militants hungry for action after the disbandment of JI. They flocked to him, according to a counter-terrorism expert.
A prison source said that Aman's flair for Arabic allowed him to hold court among men like Santoso, Bahrumsyah, Bahrun and Abu Jandal, as well as other inmates such as JI bombmaker Musola alias Muhamad Ibrahim Musa and Iwan Darmawan Muntho alias Rois, who is on death row for the bombing of the Australian Embassy in Jakarta in 2004.
Aman had pledged his allegiance to ISIS in 2014, according to police and intelligence sources, but he is believed to have started communicating with the group's leadership in Syria and ordering his followers to emigrate to the caliphate from 2013.
Hundreds are estimated by researchers to have made the journey so far, but proof of his growing control over militants in Indonesia is in how he has managed to merge various extremist groups under his Jemaah Anshar Khilafah terror network last year.
The brazen siege by his followers on the capital last month, however, will now serve as a clear manifestation of that dominance and reflects the threat that Aman presents to security in the region.