How long did the Thirty Years' War last?

30 years.....1618-1648
30 years
The conflict known as the Thirty Years' War lasted for about 30 years, from 1618 to 1648. It began as a religious conflict involving the Holy Roman Empire, and took place mostly in areas now part of modern Germany.
The war, or wars, lasted thirty years, from 1618 to 1648.