Isnilon Totoni Hapilon

According to the Federal Bureau of Investigation and the United States Department of State Rewards for Justice Program Hapilon was born on March 18, 1966 in Bulana barangay, Lantawan municipality, Basilan province, Republic of the Philippines.

The US government describes him as "skinny; may have chin hair and slight mustache" and his personality as "likable by peers; proud and confident in his abilities." He is a slim man with his height variously given at 5'6" or "approximately 5'5" to 5'7"" and his weight as 120 pounds. His complexion is described as "tan" or "light-skinned".

According to the FBI he goes by aliases including Abu Musab, Sol, Abu Tuan, Esnilon, and Salahuddin. The Rewards for Justice Program lists further aliases including Abubakar Hapilon, Amah Hi Omar, Abu Omar, Abubakar, Bakkal. He speaks Tausug, Tagalog, and Yakan, as well as English. His whereabouts are unknown; he may have traveled to Saudi Arabia and Malaysia.

Abu Sayyaf

In 2002 Hapilon and four other ASG members -- Khadaffy Janjalani, Hamsiraji Marusi Sali, Aldam Tilao, and Jainal Antel Sali, Jr.—were indicted in Guam and in the United States for their role in the 2000 Dos Palmas kidnappings of 17 Filipinos and three Americans, and the eventual beheading of one of the Americans, Guillermo Sobero. Hapilon is the only one of the five indicted who is still alive. On February 24, 2006, Hapilon, along with Janjalani and Jainal Sali, Jr. was added to the FBI's Most Wanted Terrorists list. The Rewards For Justice Program of the United States Department of State is offering up to US$5 million (approx. 230,000,000 Philippine pesos as of August 2010) for information on Hapilon's location.

Hapilon was wounded in April 2013 in an army offensive that killed eight other rebels in the southern Philippines. Hapilon was hit during a raid but his followers managed to drag him off safely before soldiers could seize control of the rebel base.

There are reports that he suffered a stroke at some point.

Islamic State in the Philippines (ISIP)

Sometime in 2013–2014, Abu Sayyaf released a video confirming that Isnilon was alive. In the video, he claimed to have officially broken up with al-Qaeda and defected to Abu Bakr al-Baghdadi and to ISIS.

According to Major Filemon Tan Jr., spokesperson of the Western Mindanao Command, Hapilon led an attack alongside Furuji Indama at Tipo-Tipo, Basilan on July 7, 2016. Former Ungkaya Pukan town mayor Joel Maturan said, "the whole village of Sungkayot is affected." "The bandits are firing at villages and targeting the headquarters of 18th Infantry Battalion using 50 caliber (guns)," Maturan said. Maturan said he was leading his own barangay tanods (village watchmen) in support of the military troopers.

Former Tipo-Tipo Central town Mayor Tong Istarul said the bandits stormed the Tipo-Tipo town proper around 7:30 p.m. and displaced thousands of residents. "Nagkagulo, lahat apektado (It turned chaotic, everybody was affected), I can’t give numbers. We will wait until tomorrow, mahirap ngayon (it’s difficult to get information now)", Istarul said.

The previous report is part of the on-going Battle of Tipo-Tipo which is centered on Tipo-Tipo as well as Ungkaya Pukan and Al-Barka.

A June 21, 2016 video by the Islamic State entitled 'The Solid Structure' refers to Hapilon as 'al-mujahid al-muwakkal li-qiyadat junud ad-dawla al-islamiyya f-il-filibin' ('the mujahid authorized to lead the soldiers of the Islamic State in the Philippines') and al-amir ('the emir').

As of January 2017, ISIL acknowledged him as their member. And he is known to be in Butig, Lanao del Sur for rectifying Maute Group and joins Abu Sayyaf to establish the Islamic State in the Philippines. He was later promoted to Emir of the "Philippine Province".

In May 2017, during a joint operation of the Armed Forces of the Philippines and the Philippine National Police to capture Hapilon, militants of the Maute group launched an attack in Marawi. As of this time, Isnilon is in Marawi, alongside his supporters