Afghan insurgency's reclusive leader - Mullah Omar. -Reuters

According to Taliban biographers, Mullah Omar was born in the Chah-i-Himmat village of Khakrez district in Kandahar, Afghanistan in the year 1960. His father Maulvi Ghulam Nabi was a religious scholar as were other members of his family.

After the death of his father, Mullah Omar moved to Deh-Rawood district of Uruzgan province where he sought religious education under the supervision of his paternal uncles Maulvi Muhammad Anwar and Maulvi Muhammad Jummah.

At the age of eight, Mullah Muhammad Omar joined the primary seminary of Shar-i-Kohna area in Deh-Rawood district.

Read: Taliban leader Mullah Omar is 'dead': BBC report

After the Soviet invasion of Afghanistan in 1979, Mullah Omar joined the fight against the Soviets and rose to prominence as a “tough fighter” and an “efficient commander”.

In 1992, after the collapse of Afghan president Dr Najibullah's government and with the eruption of civil war between various mujahideen factions, Mullah Omar ceased combat activities and set up a religious seminary in Gishaan village of Sang-i-Hisaar area of Maiwand district in Kandahar province. He then continued with his religious studies along with his former mujahideen colleagues after the war against the Communist forces.

Maulvi Sadiq, a Taliban official in Kandahar province said in 2011 that after the Soviet withdrawal, the creation of the Taliban movement and its subsequent advance was triggered by the kidnapping and rape of a young girl in Kandahar by a local warlord.

Read more: US may not target Mullah Omar after this year

According to him, Mullah Omar and some of his old colleagues decided to take on the warlord who had allegedly kidnapped and raped the girl. Other seminary students also joined them and the group transformed into the Taliban movement of the 1990s.

The government of Afghanistan under the Taliban was referred to as the ‘Islamic Emirate of Afghanistan’ and was formed with an initial cadre 1,500 religious scholars and seminary students from Afghanistan, who pledged allegiance to Mullah Omar.

The initial pledge of allegiance eventually gained momentum and spread to other areas, with many religious scholars from the region pledging support. Around this time, Saudi billionaire Osama bin Laden along with his entourage comprising hundreds of Arab fighters and commanders moved to Afghanistan and pledged allegiance to Omar.

Al Qaeda emerged and its ties with the Taliban movement grew strong in a short period of time, especially post-911, when Mullah Omar refused to hand over bin Laden to the United States.

Further reading: Taliban warn IS leader not to interfere in Afghanistan

In addition to bin Laden and Ayman al-Zawahiri, Al Qaeda's top tier commanders such as Mustafa Abu Yazid, Abu Yahya al-Libi, Sheikh Issa al-Masri and others were successful in influencing the Taliban, convincing them to change many of their opinions, from issues of Islamic jurisprudence to the general worldview that shifted from an Afghan-centric mindset to that of global jihad.

Despite public statements from the Taliban which have given the impression of a local resistance movement, the Afghan Taliban have once again provided sanctuaries to Al Qaeda operatives — this time to the fighters escaping operation Zarb-i-Azb in Pakistan.

Mullah Omar was recently confronted with a new challenge — the rise of Abu Bakr al-Baghdadi’s self-styled Islamic State.

For now, the majority of Islamist militant groups seem to have preferred Mullah Omar's softer approach rather than Baghdadi's brutality.