Mullah Mansoor was born in around 1965 in a small village called Kariz in the Maiwand district of Kandahar. He belongs to Afghanistan's Ishaqzai tribe.
He fought against Soviet forces in Afghanistan for a brief period and was a member of Harakat-i-Inqilab-i-Islami, a former paramilitary group formed by Maulana Mohammad Nabi Mohammadi to fight them.
One of his first jobs for the group was overseeing the security of Kandahar airport.
In 1996-2001, when the Taliban was in power, he oversaw ministry of civil aviation.
He rose to the upper echelons after Mullah Akhtar Osmani, a senior Taliban military leader and a close associate of Mullah Omar, was killed by US-led coalition forces in 2006 and Mullah Dadullah Akhund, the group's top military commander, was killed in 2007 by British special forces.
Between 2007 and 2010 he was able to stake a claim for higher office when Mullah Abdul Ghani Baradar, the deputy of Mullah Omar, and Mullah Obaidullah Akhund, the Taliban government defence minister, were captured by the Pakistan Intelligence agency ISI.
In July 2015, Afghan intelligence said that Mullah Omar had been dead for two years. Within hours of that announcement, the Taliban reportedly held a meeting and elected Mullah Mansoor as leader. But his appointment appeared to expose fissures in the group.
A few months after his appointment, Taliban fighters seized the capital of Kunduz province after launching a daring raid from multiple directions. The attack was the biggest blow to President Ashraf Ghani since he took office a year before.
In December 2015, Afghan officials said Mansoor had died after a gunfight. The Taliban later released an audio message from him in which he denied he had been killed.
Mansoor refused to join any of the Quadrilateral Coordination Group (QCG) meetings, made up of representatives from Afghanistan, Pakistan, China and the United States and aimed at reviving a peace process.
After his persistent refusal to join talks, Afghan officials told Al Jazeera that action against the Taliban would be on the agenda for the fifth round of peace talks in early May.
US officials briefed the media on May 21 that a drone attack authorised by President Barack Obama had "likely killed" him and another Taliban member.
With additional reporting by Shereena Qazi.
Source: Al Jazeera and agencies