In 41 AD, the veteran Han general Ma Yuan led 20,000 troops against the Trưng Sisters. His advance was checked by Cổ Loa Citadel for over a year, but the Lạc lords became increasingly nervous at the sight of a large Han army. Realizing that she would soon lose her followers if she did not do anything, Trưng Trắc sallied out against the Han army and lost badly, losing more than 10,000 followers. Her followers fled, allowing Ma Yuan to advance. By the end of 42 AD, both sisters had been captured and executed.