Hong Kong was leased by the British for 99 years (lease terms were set after British beat Chinese in opium wars, giving British drug dealers the right to sell o

Hong Kong was leased by the British for 99 years (lease terms were set after British beat Chinese in opium wars, giving British drug dealers the right to sell opium to Chinese citizens). After 99 years, China was strong enough where British couldn’t reasonably renege on lease or force new terms, so they gave it back to China.