In 108 B.C. Emperor Wu of the Han Dynasty conquered the area under Youqu (右渠), a grandson of Wei Man. The Emperor set up Lelang, Lintun, Xuantu and Zhenfan commanderies in the Korean Peninsula. Lelang was located in northwestern Korea and consisted of 11 prefectures. Its capital was put near P'yŏngyang. (Rangnang 樂浪/락랑 is a district in central P'yŏngyang today.)
After Emperor Wu's death, Zhenfan and Lintun were abolished and Xuantu was moved to Liaodong. Some prefectures of the abolished commanderies were incorporated into Lelang. Lelang after the consolidation is sometimes called "Greater Lelang commandery". Since Lelang became too large for a commandery, the Defender of the Southern Section (南部都尉) was set up to rule the seven prefectures which formerly belonged to Zhenfan. Before that, the Defender of the Eastern Section (東部都尉) was put to rule former Lintun's seven prefectures.
Massive Chinese immigrations, mainly from Yan (Hebei) and Qi (Shandong), continued without cessation, implanting Chinese cultures in the peninsula. The Yan people came from Beijing via Liaodong and the Qi people came across the Yellow Sea. Among them, the Wang clan, whose ancestor is said to have fled there from Qi in the 2nd century B.C., became powerful. It is presumed that most of Lelang Chinese spoke the Yan dialect.
While the Han Dynasty was took over by Wang Mang and China fell into chaos, Wang Tiao (王調) started a rebellion and broke away from China. In 30 A.D. the rebellion was crushed by Wang Zun (王遵), whom Emperor Guangwudi appointed as Governor of Lelang. Lelang came under the direct control of China again. However, the shortages of human resources caused by the turmoil resulted in the abolishment of eastern seven prefectures. The administration was left to the Hui (濊) natives, whose chieves were conferred marquisate.
At the end of the Eastern Han Dynasty, Gongsun Du, appointed as the Governor of Liaodong in 184, extending his semi-independent domain to the Lelang and Xuantu commanderies. His son Gongsun Kang separated the southern half from the Lelang commandery and established the Daifang commandery in 204. As a result, the Lelang commandery reverted to its original size.
In 236 under the order of Ming Di of Kingdom of Wei, Sima Yi crushed the Gongsun family and annexed Liaodong, Lelang and Daifang to Wei. Lelang was inherited by the Jin Dynasty. Due to bitter civil wars, Jin became unable to control the Korean peninsula at the beginning of the 4th century. Zhang Tong (張統) broke away from Jin in Lelang and Daifang. After Luoyang, the capital of Jin, was occupied by the Xiongnu in 311, he went for help to Murong Hui, a Xianbei warlord, with his subjects. Murong Hui put another small Lelang commandery in Liaodong. The former Lelang was annexed by Goguryeo.