I think the brothers Mauser's (Paul and Wilhelm) first rifle was the Infanterie-Gewehr Mod. 71 German Mauser and was the first regulation brass cartridge rifle of the Imperial German Army. It was a split bridge, single-shot in 11mm (11.15 x 60R)with a diameter of .446, and only a single locking lug forward of the receiver. It was later converted to a tubular magazine repeater as the Model 71/84.
Not quite the workhorse the more well known later Mausers were. Most folks think of the M98 when they hear "Mauser" but as 1SHOT pointed out, there is quite a family of quality Mausers to be looked at and appreciated.....some are still highly sought after as platforms for custom rifles.