Renault FT at Bovington Tank Museum, Dorset
While British tanks like the Mark I and Mark IV were multi-crew and featured guns mounted in side sponsons or casemates, the French went for a two-man tank with a revolving turret. This was the first turreted tank to see service.
While it was faster than the heavier British vehicles its short length restricted its ability to cross the German trenches. However the Renault FT did introduce the revolving gun turret into tank design. The turret mounted either a 37mm gun OR a Hotchkiss machine gun [this one has a Hotchkiss] and the design was so successful that it was used for many years after WW1.
The French army still used the Renault FT in 1940 and many were captured and re-used by the Germans - mainly for towing aeroplanes on airfields or for airfield defence. Turrets were stripped from some vehicles and re-used on pillboxes in the Atlantic Wall. Some FTs still being used by the Germans around Carpiquet Aerodrome, Normandy, in 1944. Others were deployed on the streets of Paris later the same year.
My full set can be found here in approximate chronological order of service: www.flickr.com/photos/barryslemmings/sets/72157594476965425/