US Afghanistan commander General David Petraeus formally relinquished command Monday to General John Allen, the Associated Press results.
Patraeus is leaving his post to don the mantle of Director of Central Intelligence in September, where White House officials hope his 'consumers eye' for intelligence data will help refocus US intelligence collection efforts in Central Asia.
General Allen, his replacement, made his name in Iraq by forging cooperative alliances with Sunni leaders.
The handover took place at a change of command ceremony in Kabul, just hours after a key adviser to Afghan President Hamid Karzai was shot dead in a four-hour raid on his home in the heavily protected capital.
Petraeus' legacy in Afghanistan remains in question, as violence continues to rage, underscored by the shock killings of two of Karzai's top allies in the south, his brother last Tuesday, and a senior adviser on Sunday.
But many analysts say Patraeus inability to quell the Taliban and Al-Qaeda directed insurgency into Afghanistan was signed and sealed by the Obama administration telegraphing its intention to draw down troop strength, which has emboldened the insurgents intent on making a show of strength.
Armed attackers murdered senior adviser Jan Mohammad Khan, the former governor of southern Uruzgan province, in a raid on his Kabul home on Sunday. The assassination came just days after the president's half-brother Ahmed Wali Karzai was shot dead by his own head of security at his home in the southern province of Kandahar.
The Taliban have claimed responsibility for both the killings.