Ngô Quyền in 938 declared himself king, but died after only 6 years. His untimely death after a short reign resulted in a power struggle for the throne, resulting in the country's first major civil war, the upheaval of the Twelve Warlords (Loạn Thập Nhị Sứ Quân). The war lasted from 944 to 968, until the clan led by Đinh Bộ Lĩnh defeated the other warlords, unifying the country.^[123] Đinh Bộ Lĩnh founded the Đinh dynasty and proclaimed himself Đinh Tiên Hoàng (Đinh the Majestic Emperor) and renamed the country from Tĩnh Hải quân to Đại Cồ Việt (literally "Great Viet"), with its capital in the city of Hoa Lư (modern-day Ninh Bình Province). The new emperor introduced strict penal codes to prevent chaos from happening again. He then tried to form alliances by granting the title of Queen to five women from the five most influential families. Đại La became the capital.

In 979, Emperor Đinh Tiên Hoàng and his crown prince Đinh Liễn were assassinated by Đỗ Thích, a government official, leaving his lone surviving son, the 6-year-old Đinh Toàn, to assume the throne. Taking advantage of the situation, the Song dynasty invaded Đại Cồ Việt. Facing such a grave threat to national independence, the commander of the armed forces, (Thập Đạo Tướng Quân) Lê Hoàn took the throne, replaced the house of Đinh and established the Early Lê dynasty. A capable military tactician, Lê Hoan realized the risks of engaging the mighty Song troops head on; thus, he tricked the invading army into Chi Lăng Pass, then ambushed and killed their commander, quickly ending the threat to his young nation in 981. The Song dynasty withdrew their troops and Lê Hoàn was referred to in his realm as Emperor Đại Hành (Đại Hành Hoàng Đế).^[124] Emperor Lê Đại Hành was also the first Vietnamese monarch who began the southward expansion process against the kingdom of Champa.

Emperor Lê Đại Hành's death in 1005 resulted in infighting for the throne amongst his sons. The eventual winner, Lê Long Đĩnh, became the most notorious tyrant in Vietnamese history. He devised sadistic punishments of prisoners for his own entertainment and indulged in deviant sexual activities. Toward the end of his short life – he died in 1009 at the age of 24 – Lê Long Đĩnh had become so ill, that he had to lie down when meeting with his officials in court.^[125]