Agha Muhammad Yahya Khan (4 February 191710 August 1980) was a Pakistani four-star rank general who served as the third president of Pakistan from 1969 to 1971, under martial law. His presidency oversaw a civil war in East Pakistan, resulting in Bangladesh's secession. He also served as the fifth commander-in-chief of the Pakistan Army from 1966 to 1971.

Khan was commissioned into the British Indian Army in 1939 and fought in the Second World War in the Mediterranean theatre. Following the partition of British India, he joined the Pakistan Army and was placed in charge of organising the Staff College in Quetta. In 1965, he played a vital role in executing Operation Grand Slam in Indian-administered Kashmir during the second Indo-Pakistani war and was assigned to assume the command of the army in September 1966 by President Ayub Khan. In the wake of nationwide protests against Ayub Khan's government, he resigned from the presidency and transferred authority to Yahya Khan in March 1969.

Upon taking over the presidency, Khan declared martial law and suspended the constitution. He issued the Legal Framework Order in July 1970 and held the country's first general election in December 1970, with which the Awami League from East Pakistan emerged victorious with a national majority. He barred power transition to the party's leader Sheikh Mujibur Rahman, leading to mass protests and civil disobedience in the east and a call for sovereignty. On 25 March 1971, Khan ordered Operation Searchlight in an effort to suppress Bengali nationalism which initiated a genocide; and led to the declaration of independence of East Pakistan as Bangladesh by Sheikh Mujibur Rahman, and start of a civil war in the east. He is considered a chief architect of the Bangladesh genocide along with his deputies Abdul Hamid Khan and Tikka Khan. In December 1971, Khan ordered pre-emptive strikes against the Mukti Bahini-allied Indian Army, resulting in another war with India. The two simultaneous wars resulted in the surrender of Pakistani forces in the east and Bangladesh's secession, after which Yahya Khan resigned from the army command and transferred the presidency to Zulfikar Ali Bhutto. Khan remained under house surveillance prior to 1979 when he was released by Fazle Haq. Khan died the following year in Rawalpindi and was buried in Peshawar.

Khan's brief period in power is widely regarded as a pivotal factor in the division of Pakistan. His refusal to hand over power to the Awami League, despite their electoral victory in East Pakistan, sparked political unrest. This culminated in Operation Searchlight: a brutal military crackdown resulting in the Bengali genocide and causing widespread death and displacement. Khan is viewed negatively in both Bangladesh, where he is considered the architect of the genocide, and Pakistan, where his failure to prevent the country's disintegration is regarded as a national tragedy.

Early life and education Yahya Khan, whose full name was Agha Muhammad Yahya Khan Qizilbash, was born during the British Raj, on 4 February 1917 in the town of Chakwal.Democracy, security, and development in India. By Raju G. C. Thomas. Born in a Qizilbash family from Peshawar, he was also described as a Pashtun and claimed descent from the elite soldiers of Iranian conqueror Nader Shah (). Yahya Khan also spoke Persian. Yahya's father, Saadat Ali Khan (b. 28 Nov 1883), was originally from Peshawar. Saadat Ali Khan worked in the Indian Imperial Police, in the Punjab Province. He joined as a head constable and retired as a deputy superintendent in 1938. He was posted in Chakwal when Yahya Khan was born. Saadat was rewarded with the title of Khan Sahib for having disposed of the bodies of many independence activists, including Bhagat Singh, as they were executed in secrecy and the colonial authorities wanted to dispose of the corpses without attracting much attention, operations Saadat Ali Khan carried out "efficiently and faithfully."

Their family house, built in 1890, is located in the Muhallah Shaikh Ul Islam street of Ganj area in Peshawar's Walled City, once serving as the main administrative area. Yahya studied in the prestigious Colonel Brown Cambridge School in Dehradun and later enrolled at the University of the Punjab in Lahore, from where he graduated with a B.A. degree, finishing first in his class.

Military career (1939–1969) British Indian Army (1939–1947) Yahya Khan was commissioned into the British Indian Army from the Indian Military Academy, Dehradun on 15 July 1939, his date of commission was later antedated to 28 August 1938. An infantry officer from the 4th/10th Baluch Regiment (4th Battalion of 10th Baluch Regiment, later amalgamated with the modern and current form of Baloch Regiment, 'Baloch' was spelled as 'Baluch' in Yahya's time), Yahya saw action during World War II in North Africa where he was captured by the Axis Forces in June 1942 and interned in a prisoner of war camp in Italy from where he escaped in the third attempt.

Yahya Khan served in World War II as a lieutenant and later captain in the 4th Infantry Division (India). He served in Iraq, Italy and North Africa.

Pakistan Army (1947–1971) After the partition of India, he decided to join the Pakistan Army in August 1947, he had already reached the rank of major (acting lieutenant-colonel). In this year, he was instrumental in not letting the Indian officers remove books from the library of the Staff College, Quetta where Yahya was posted as an instructor at the time of the partition. He renamed the 'Command and Staff College' from 'Army Staff College'. At the age of 34, he was promoted to Brigadier, then the youngest Brigadier of Pakistan. And then he was appointed as commander of the 105th Independent Brigade that was deployed in LoC ceasefire region in Jammu and Kashmir in 1951–1952.

Later Yahya Khan, as Vice Chief of General Staff, was selected to head of the army's planning board set up by General Ayub Khan to modernise the Pakistan Army in 1954–57. Yahya also performed the duties of Chief of General Staff from 1957 to 1962 from where he went on to command two infantry divisions from 1962 to 1965. He played a pivotal role in sustaining the support for Ayub Khan's campaign in the 1965 presidential elections against Fatima Jinnah. He was made GOC of the 7th Infantry Division of the Pakistan Army, which he commanded during the 1965 war with India.

During these years, Yahya was also tasked in civil and administrative matters, including being the Administrator of the Islamabad Capital Project, "the job for major execution" being given to him.

Commander-in-Chief (1966-1971) Yahya became the Pakistan Army's C-in-C on 18 September 1966 when General Musa Khan retired. Yahya superseded two of his seniors: Lieutenant-General Altaf Qadir and Lieutenant-General Bakhtiar Rana.

After becoming the commander-in-chief of the army, Yahya energetically started reorganising the Pakistan Army in 1966. The post-1965 situation saw major organisational and technical changes in the Pakistan Army. Until 1965, it was thought that divisions could function effectively while getting orders directly from the army's GHQ. This idea failed miserably in the 1965 war, and the need to have intermediate corps headquarters in between the GHQ and the fighting combat divisions was recognised as a foremost operational necessity after the 1965 war. In the 1965 war, the Pakistan Army had only one corps headquarters (the 1 Corps).

Soon after the war had started, the United States had imposed an embargo on military aid to both India and Pakistan. This embargo did not affect the Indian Army but produced major changes in the Pakistan Army's technical composition. US Secretary of State Dean Rusk well summed it up when he said, "Well if you are going to fight, go ahead and fight, but we're not going to pay for it".Dennis Kux, India and the United States: Estranged Democracies (Washington, DC: National Defense University Press, 1992), 239.

Pakistan now turned to China for military aid, and the Chinese tank T-59 started replacing the US M-47/48 tanks as the Pakistan Army's MBT (Main Battle Tank) from 1966. 80 tanks, the first batch of T-59s, a version of the Russian T-54/55 series were delivered to Pakistan in 1965–66. The first batch was displayed in the Joint Services Day Parade on 23 March 1966. The 1965 War had proved that Pakistan Army's tank-infantry ratio was lopsided and more infantry was required. Three more infantry divisions (9, 16 and 17 Divisions) largely equipped with Chinese equipment and popularly referred to by the rank and file as "The China Divisions" were raised by the beginning of 1968. Two more corps headquarters: the 2 Corps Headquarters (Jhelum-Ravi Corridor) and the 4 Corps Headquarters (Ravi-Sutlej Corridor) were raised, also in East Pakistan a corps-sized formation (which was titled as the Eastern Command) was created.

Presidency (1969–1971) A sustained anti-regime mass movement began in the fall of 1968 in West Pakistan. The uprising spread to East Pakistan and gathered strength, adding to a tense political climate that had worsened following President Ayub Khan's implementation of the 1966 Tashkent Agreement and sacking of Foreign Minister Zulfikar Ali Bhutto. Ayub Khan tried to quell the revolt by making concessions to opposition groups including the Pakistan Peoples Party (PPP) and the Awami League (AL), but demonstrations continued.

Rather than resigning and allowing a constitutional transfer of power, Ayub Khan requested that Yahya Khan, Commander-in-Chief of the Army, utilise the military's supra-constitutional authority to declare martial law and take power. On 24 March 1969, Ayub directed a letter to Yahya inviting him to deal with the crisis, as it was "beyond the capacity of [civil] government to deal with the... complex situation." Some sources claim Yahya accepted Ayub's proposal on 25 March. On 26 March 1969, General Yahya appeared on national television and announced a state of martial law throughout the entirety of the country. The 1962 constitution was abrogated, the parliament was dissolved, and Ayub's civilian officials were dismissed. In his first nationwide address, Yahya maintained, "I will not tolerate disorder, let everyone remain at his post."

Yahya Khan's new military government featured several active duty military officials:

+ Yahya Khan administration Ministers Portrait Ministries and departments Inter-servicesGeneral Yahya Khan President and Chief Martial Law AdministratorInformation and BroadcastingLaw and JusticeForeign and Defence General Abdul Hamid Khan Deputy CMLAInterior and Kashmir Affairs Vice-Admiral S. M. Ahsan Deputy CMLAFinance and Planning CommissionStatistics, Commerce, and Industry Pakistan NavyAir Marshal Nur Khan Deputy CMLACommunications and HealthLabour and Science and Technology

When Yahya Khan assumed the office on 25 March, he inherited a two-decade constitutional problem of inter-provincial ethnic rivalry between West Pakistan, which was almost exclusively Muslim and was dominated by the Punjabi-Pashtun-Mohajir peoples, and East Pakistan, whose population was largely ethnically Bengali and approximately three-fourths Muslim (as of the 1961 Census). In addition, Yahya also inherited the challenge of transforming a country essentially ruled by one man into a democratic country, which was the ideological basis of the anti-Ayub movement of 1968–69. Once in office, Yahya Khan was tasked with leading the country, drafting of a provisional constitution, resolving the One Unit question, and satisfying the frustrations and the sense of exploitation stirring in the "East Wing" (East Pakistan) by government policies since 1948.

The American political scientist Lawrence Ziring observed: