The Char B1 was one of the most produced and widely used indigenous French tank designs employed during the Invasion of France in 1940. The Char B1 came in three modifications, with the ter modification marking the third and final one. Each modification brought with it several changes that would improve the design’s overall performance, from the installation of more powerful engines, over enhanced armour protection and anti-tank capabilities to increased ammunition count. Although the Char B1’s development began as early as the mid 1920s, the B1ter version was conceived around the same time the Char B1bis entered serial production, in 1937.

Compared to the B1bis, the ter modification featured thicker frontal armour protection, going up to 75mm. Apart of the extra armour, the B1ter was also equipped with a more powerful 350 hp engine as well as a different transmission and received space for an additional crew member too. These changes increased the weight of the vehicle up to 36.6 tonnes, but also made the planned production process a lot easier, faster and most importantly, cheaper. The first prototype of the Char B1ter was constructed and shown off to French military officials in 1937, with testing and production approval following in May 1940. However, at that point, it was a case of too little too late for the Char B1ter. Three further prototypes were constructed before France capitulated in June 1940, with efforts to evacuate the prototypes from France ultimately failing, as the ship transporting the vehicles was sunk by a German air raid on 21 June 1940.