How Pathan Ayub Khan was promoted to Four-Star Rank?

From the creation of Pakistan to the separation of Bengal, not a single Punjabi was posted as Pakistan Army Chief. After completion of General Sir Douglas Gracey term on 16 January 1951, there were three senior general officers in the line of promotion for four-star assignment; first general officer being a Major-General Iftikhar Khan (Punjabi) while others were Major-Generals Akbar Khan Minhas (Punjabi) and N.A.M Raza (Punjabi). Initially, it was General Iftikhar Khan (Punjabi) who was promoted to four-star rank and appointed as first native Chief of Army Staff, but he died in a plane crash en route to his senior officer training in the United Kingdom before taking his charge as Pakistan Army Chief.

After the death of General Iftikhar Khan (Punjabi), the senior-most officer of the Army was Major-General Ishfakul Majid (Bengali) and he was senior to Ayub Khan (Pathan) as well. Meanwhile, Defense Secretary Major-General Iskandar Mirza (Bihari but a resident of Bengal) and Prime Minister Liaquat Ali Khan (Urdu Speaking UP-ite Muhajir) played an instrumental role in Ayub's promotion to appoint Ayub Khan to Four-Star Rank and Chief of Army Staff.