Gulbuddin Hekmatyar, who returned to Kabul Thursday after more than 20 years, is one of Afghanistan's most notorious warlords, chiefly remembered for his siege of the capital in the bloody civil war of the 1990s.
A former prime minister, Hekmatyar was a prominent anti-Soviet commander in the 1980s and stands accused of killing thousands of people in Kabul from 1992 to 1996, a period when various mujahideen factions fought each other for supremacy and which ended when the Taliban emerged victorious.
Widely lambasted as the "butcher of Kabul", during his exile he was long believed to be living in hiding in Pakistan, though his group had claimed he was inside Afghanistan.
Following the 2001 US-led invasion of Afghanistan and fall of the Taliban, the US State Department designated him a terrorist, accusing him of taking part in and supporting attacks by Al-Qaeda and the Taliban.
But his Hezb-i-Islami militant group has been largely inactive in recent years, with its last big attack in Afghanistan, which killed 15 people -- including five Americans -- in 2013.
Many Afghans remember Hekmatyar for overseeing the massive shelling of Kabul in the early 1990s -- despite being named prime minister in 1992. His other nickname is "Rocketyar".
Now believed to be aged near 70, he is the latest among a series of controversial figures that Kabul has sought to reintegrate into Afghan politics in the post-Taliban era.
His return comes seven months after he signed a landmark peace deal with Kabul, marking a symbolic victory for President Ashraf Ghani, who has struggled to revive peace talks with the more powerful Taliban.
As a mujahideen leader Hekmetyar enjoyed considerable support from Pakistan and Saudi Arabia, but eventually Islamabad gave up its support and backed the Taliban movement instead. The Taliban forced Hekmatyar out of Kabul in 1996.
He was also linked to serious human rights abuses, including the forced disappearance of political opponents and an underground prison in Pakistan where torture was routine, according to Human Rights Watch.
"Bolstered by US military aid funnelled through Pakistan in the 1980s, Hekmatyar extended his reach to include targeted assassinations of Afghan intellectuals in Pakistan and violent attacks on nongovernmental organisations that ran education and health programs for Afghan women in refugee camps in Pakistan," the group has written.
But he is far from alone in enjoying impunity -- no former Afghan warlord has been held to account. Indeed Abdul Rashid Dostum, another notorious former commander, has been the country's vice president since 2014.
Hezb-i-Islami has been trying to repair Hekmatyar's public image as it attempts to rebrand from a radical, misogynistic movement to a mainstream political force.
Prior to the September deal, the US State Department had said Washington was not involved in the talks but welcomed the potential truce with Hekmatyar.
In February the UN Security Council lifted its sanctions on Hekmatyar, theoretically opening the way for his return to Kabul and mainstream political life.