Who they were
Born Nguyen Anh in 1762, he was nearly the sole survivor when the Tay Son destroyed the southern Nguyen lords in 1777. From the Mekong delta he fought back for a quarter century, aided by volunteers, ships and arms organized by the French bishop Pigneau de Behaine.
What they did
Victorious in 1802, he ruled as Gia Long the first state stretching the full length of present-day Vietnam, from the capital at Hue. The name Viet Nam was adopted in 1804 in exchanges with the Qing court. His administration issued the Gia Long law code, closely modeled on the Qing code, and built roads and land registers.
Legacy
Assessments diverge: he is credited as the unifier who built the framework of modern Vietnam, and criticized for the French openings his war debts created and for the conservative order he entrenched. Both readings shape his place in Vietnamese history.