Beijing is a city.
Beijing ( formerly romanised as Peking ) is the capital of the People 's Republic of China and the world 's third most populous city proper . It is also one of the world 's most populous capital cities . Beijing is the second largest Chinese city by urban population after Shanghai and is the nation 's political , cultural , and educational centre . Beijing was the largest city in the world by population for much of the second millennium A.D. .