of Han (r. 141–87 BC), the travels of the diplomat Zhang Qian opened up China's relations with many different Asian territories for the first time. While traveling to the Western Regions in order to seek out an alliance with the Yuezhi against the Xiongnu, Zhang Qian was imprisoned by the Xiongnu for many years, but he brought back detailed reports of lands that had been previously unknown to the Chinese. This included details of his travels to the Greek-Hellenized kingdoms of Fergana (Dayuan) and the Greco-Bactrian Kingdom (Daxia), as well as reports of Anxi (Persian Empire of Parthia), Tiaozhi (Mesopotamia), Shendu (India), and the Wusun Central Asian nomads. After his travels, the famous land trading route of the Silk Road leading from China to the Roman Empire was established. Emperor Wu was also known for his conquests and successful campaigns against the Xiongnu. He warred against the Kingdom of Wiman Joseon in order to establish the Four Commanderies of Han in Manchuria, one of which was established in northern Korea, the Lelang Commandery. The empire began expanding into southern China and northern Vietnam, then the territory of the Baiyue kingdoms. The Han Empire absorbed Minyue after defeating the state, and annexed the Dian in Yunnan. By 111 BC, Emperor Wu conquered the Nanyue kingdom in the Han–Nanyue War. Nanyue was ruled by the Triệu dynasty since the Qin naval officer Zhao Tuo had broken ties with mainland rule in the fall of Qin and establishment of Han. Yet Chinese trading missions to follow were not limited to travelling across land and terrain. During the 2nd century BC, the Chinese had sailed past Southeast Asia and into the Indian Ocean, reaching India and Sri Lanka by sea before the Romans. This sea route became well traveled not only by merchants and diplomats, but also Chinese religious missionaries in search of further Indian Buddhist texts to translate from Sanskrit to Chinese. In AD 148, the Parthian prince known as An Shigao was the first to translate Buddhist scriptures into Chinese. There were many other Buddhist missionaries as well, including Yuezhi missionaries and Kushan Buddhist missionaries from northern India who introduced Buddhism to China. Emperor Ming establishing the White Horse Temple in the 1st century AD is demarcated by the 6th-century Chinese writer Yang Xuanzhi as the official introduction of Buddhism to China. Also by the 1st century AD, the Chinese made sea