Omarkhayam Romato Maute and Abdullah Maute are the brothers leading the militant group named after them which has laid siege to Marawi City in the Philippines.
The group declared allegiance to Daesh in 2014. Marawi City is a Muslim majority city and the largest in Lanao del Sur province on Mindanao island in the southern Philippines, a predominantly Christian (Catholic) country.
Here is what we know about them so far.
Who are the Maute brothers?
Omarkhayam is a "walking time-bomb" or so he describes himself on his Facebook page.
The two brothers grew up with several other brothers and sisters in Marawi City.
As teenagers in the 1990s, they seemed like ordinary young men, a neighbour of the Maute family said. The brothers studied English and the Koran, and played basketball in the streets. In the early 2000s, Omarkhayam and Abdullah studied in Egypt and Jordan, respectively, where they became fluent in Arabic.
Omarkhayam went to Al Azhar University in Cairo and in 2011 he settled back in Mindanao.
In Cairo "none of his fellow students saw him as having any radical tendencies at all, and photographs show a young man enchanted by his baby daughters and playing with the growing family by the Red Sea," Jakarta-based anti-terrorism expert Sidney Jones wrote in a 2016 report.
He said the Maute group has "the smartest, best-educated and most sophisticated members" of all the pro-Daesh outfits in the Philippines.
Little is known about Abdullah's life after he went to Jordan, and it is not clear when he returned to Lanao del Sur.
Why is Maute making the media rounds?
On May 23, the two brothers led a band of militants who overran Marawi City after the government tried to arrest Isnilon Hapilon of Abu Sayyaf.
Known for kidnappings, Abu Sayyaf has fought since the 1990s for an independent Islamic province in the Philippines and Hapilon was last year declared by Daesh as its Southeast Asia "emir."
Hapilon was seen in a video that emerged last week showing militants – including the Maute brothers – plotting to seal Marawi City off as a separate enclave.
The occupation of Marawi City by Maute, a group hardly heard of a year ago, has become the biggest security challenge of President Rodrigo Duterte's 11-month presidency. The militants have resisted air and ground assaults and control central parts of the city, which ahead of the siege had a population of 200,000. Most of them have since fled.
Daesh claimed responsibility for the occupation and subsequent rampage through the city on its Amaq news agency.
President Duterte declared martial law on Mindanao island and sent in the military to end the siege, now entering its third week.
Duterte defended his decision to declare martial law as necessary to prevent the spread of extremism in the impoverished region.
Who is the "heart of the Maute organisation"?
According to a neighbour, Farhana Maute, who ran furniture and used-car businesses, helped finance the group. She reportedly drove recruitment and radicalisation of local youths.
Military spokesman Lieutenant Colonel Jo-Ar Herrera said the Maranao clan, to which the Mautes belong, has a matriarchal tradition, and so their mother plays a central role in her sons' lives.
On Friday, she was stopped outside Marawi in a vehicle loaded with firearms and explosives and taken into custody. It was a major blow for the militants, according to Herrera, as she was the "heart of the Maute organisation."
The brothers' father Cayamora Maute, an engineer, was arrested 250 kilometres (155 miles) away in Davao City, on Thursday.
Regional police believe he can influence his sons to stop the fighting.
How do they recruit?
Samira Gutoc-Tomawis, a local civic leader who knows some of the extended Maute family, said the brothers rely heavily on social media to recruit young followers and spread their "rigid and authoritarian" ideology.
"The Mautes are very active online. They upload their ideas on YouTube," she said. "They are articulate, they are educated, they are idealistic."
The military's social media-monitoring team identified 63 accounts under fake names that it believed were being used by the Maute group and its sympathisers.
Why Marawi City?
Marawi City historically is the centre of Islam on Mindanao, a sprawling island where violent resistance to authority has been a tradition since the era of Spanish colonialism. This was further spurred in recent decades by poverty and the neglect of successive governments.
Herrera said the Maute brothers enjoy strong support in Marawi City.
"This is their place, this is where their family is, this is where their culture is, this is where the heritage is. There is a huge sympathetic perspective towards the ... Maute," he said.