The Deputy Commander-in-Chief of Defence Services is the second-highest military appointment in the Tatmadaw, the unified armed forces of Myanmar, also known in English as the "Defence Services". After the unification of Myanmar's Army, Navy, and Air Force in 1955, the Tatmadaw used the Chief of Staff system, with three branches of the armed forces led by the Vice Chief of Staff (Army), Vice Chief of Staff (Navy), and Vice Chief of Staff (Air). In 1989, this was reorganized into the current system, under which each branch is led by its own Commander-in-Chief. Since then, except in the special case of a 26-day period in 2026, the positions of the Deputy Commander-in-Chief of Defence Services and Commander-in-Chief (Army) have been traditionally combined and only one officer is appointed at a time.