Lt Gen Charles Muriu Kahariri has been promoted to the rank of General and named the Chief Defence Forces, replacing his boss Gen Francis Ogolla who died in a chopper crash.
Gen Kahariri served as Vice Chief of Defence Forces, deputising Gen Ogolla, who died along nine others last month.
Kenya Air Force commander Maj Gen John Omenda was promoted to the rank of Lt Gen and named the VCDF in the changes.
It was Gen Kahariri's lucky day as in the past, all military commanders had to have been service commanders, which he did not.
The general, who once served as deputy commander in the Kenya Navy before being promoted and posted to the defence college, had been acting CDF since April 18 when Gen Ogolla died.
Being acting CDF, the recent VCDF and a Navy man, the Defence Council was bound to name him the next boss in military tradition.
The Council, under the chairmanship of CS Aden Duale, met and briefed President William Ruto on their recommendations.
President Ruto agreed with the deliberations and announced the changes.
Gen Kahariri was also the senior most in ranking in the service. He will serve as CDF for about two more years.
The Kenya Defence Forces Act says a CDF, his deputy and service commanders shall serve a single term of four years or retire upon attaining the mandatory retirement age.
A General is supposed to retire at 62, a Lieutenant-General at 61, a Major-General at 59 and a Brigadier at 57 years.
But the Act also allows the President to, on the recommendation of the National Defence Council, extend the CDF’s term for a period not exceeding one year in times of war or emergencies like political uncertainty.
Other appointments in yesterday's changes saw Maj Gen Fatuma Ahmed named the commander Kenya Airforce, to succeed Maj Gen Omenda. She will be deputised by Brig Samuel Kipkorir.
Maj Gen Ahmed is the first woman to be named a service commander in the history of KDF. She previously held the role of senior Directing Staff Air at the National Defence College.
In the changes, Brig Paul Otieno, Managing Director for Kenya Shipyards Limited, was promoted and named the commander Kenya Navy, replacing Maj Gen Thomas Nganga who had held the position for two months.
Maj Gen Nganga was moved to the National Defence University and appointed the Vice Chancellor of administration and finance.
Brig Peter Githinji was promoted to Maj Gen and named senior directing staff at the National Defence College to replace Maj Gen Ahmed.
Also promoted was Brig George Okumu who becomes Major General and the Managing Director Kenya Ordinance Factories Corporation and Food Processing Factory.