Luy Lâu (Vietnamese) or Leilou (Chinese: t 羸婁, s 羸娄, p Léilóu) was the first capital of the Han commandery of Jiaozhi (Giao Chi) following its 111 BC submission during China's conquest of Nanyue. It was also the headquarters of the larger province of Jiaozhou and the center of China's maritime trade on the Gulf of Tonkin and South China Sea. The old citadel is at Xã Thanh Khương in Thuan Thanh in the province of Bac Ninh.
Luy Lâu became a major center for Buddhism in Vietnam. Although the Roman embassies probably arrived at the later capital Longbian, it may have been the earlier Luy Lâu that was the origin of Ptolemy's Cattigara.
- The Baxter-Sagart reconstruction of the characters' Old Chinese pronunciation is *Rojro.
- Bao Bac Ninh Thủ phủ Luy Lâu 2008 "Sau thời kì thành Cổ Loa là kinh đô nước ta thời An Dương Vương thì địa điểm Dâu (nay thuộc xã Thanh Khương - Thuận Thành) trở thành thủ phủ nước ta dưới thời Bắc thuộc kéo dài hàng nghìn năm với các tên gọi khác nhau: Luy Lâu, Liên Lâu, Dinh Lâu, Long Uyên, Long Biên.
- The Vietnam guidebook: with Angkor Wat - Page 42 Barbara Cohen, Fredric M. Kaplan - 1993 "In 111 BC, the Han Dynasty completely annexed Nam Viet as a Chinese province called Giao Chi or Chiao Chih. The town of Luy Lau, southeast of present-day Hanoi, was the ancient capital of Giao Chi. Although subjugation meant having to ..."
- Rebuilding Religious Experience- Vietnamese Refugees in America - Page 20 Linh Hoang - 2008 "However, it was only after the Chinese came to Vietnam that the Buddhists erected a center at Luy-lau which was the capital of Giao Chi and was a popular place visited by many Buddhist missionaries. Luy-lau became a major Buddhist center ."