The logical development of the earlier Hotchkiss H35, which itself was well armoured for the time, but was armed with a low velocity and calibre of 21, which was hopeless in both accuracy and armour penetration.
The H39 had a better speed and a 37/L33 main gun with good armour penetration and was supplied from 1938 and over 1200 were produced. (though some were equipped with the old 37mm main gun)
The H39 operated in conjunction principally with the Char B1s and did well in combat, though the the lack of radios and only a one crew turret, occupied by a terribly overburdened commander, were major handicaps.
The tank was liked by the Germans too, and the chassis was used for police duties as well as anti partizan operations, and some were given to Hungary and Bulgaria, and saw service on the eastern front.
21st Panzer Division particularly liked them, as the basis of armoured artillery and anti tank vehicles, both hardly beautiful, but needs must...