The People's Liberation Army Navy (PLAN or PLA Navy, Chinese: Rénmín Jiefàngjun Haijun) is the naval branch of the People's Liberation Army (PLA), the military of the People's Republic of China. Until the early 1990s, the navy performed a subordinate role to the PLA Land Forces. Since then, it has undergone rapid modernisation. It is the second largest naval service in the world. With a personnel strength of over 250,000, the PLAN also includes the 35,000 strong Coastal Defense Force and the 56,000 man Naval infantry/Marines, plus a 56,000 PLAN Aviation naval air arm operating several hundred land-based aircraft and ship-based helicopters. As part of its overall program of naval modernization, the PLAN is actively developing a blue-water navy.