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Mullah Baradar chose to touch down in the country's second biggest city Kandahar - the Taliban's spiritual birthplace and capital during their first time in power.
He arrived from Qatar, where he has spent months leading talks with the US and then Afghan peace negotiators.
Mullah Baradar was arrested in Pakistan in 2010 but freed in 2018 at the request of the Trump administration as American negotiator Zalmay Khalilzad saw him as a credible counterpart during talks in Qatar that led to the US withdrawal.
Despite his military activities, Mullah Baradar was reportedly behind several attempts to begin peace talks, specifically in 2004 and 2009, and widely seen as a potentially key part of a negotiated peace deal.
Footage released by pro-Taliban media showed crowds gathering around Mullah Baradar at the airport, pumping their fists in the air and chanting in celebration. But for those fearing reprisals from the Taliban, the emotions were opposite.