in october 2007, kayani's promotion papers for the appointment to the four-star rank was approved by the president musharraf, and appointed him as the vice chief of army staff (vcoas). at the time of the promotion, kayani ultimately superseded the senior-most army general, lt-gen. khalid kidwai, who was on an extension for one year. on 28 november 2007, kayani succeeded musharraf as chief of army staff after musharraf's retirement.