What new weapon appeared on September 15, 1916?

The tank appeared in combat on September 15, 1916. Britain first used tanks during the Battle of Flers–Courcelette, part of the wider Battle of the Somme in World War I.

The vehicle was the British Mark I, an armored, tracked machine designed to cross trenches and support infantry. Its tracks were crucial because ordinary wheeled vehicles struggled with the shell-churned ground and deep trench systems of the Western Front. The new weapon was intended to help break through defensive lines protected by machine guns and barbed wire.

The first deployment was a limited and difficult experiment. Many tanks broke down, became stuck, or could not keep up with advancing troops. Even so, the appearance of tanks marked a major change in military technology and helped establish the basic role of armored vehicles in modern warfare.

September 15 is often described as the tank’s first day in battle, not the date the technology was invented. Britain had been developing the machines in secret before the Somme offensive, and the word “tank” itself had been used as a misleading code name during development.