~ Brüderchen ergo bibamus ~
This is a line from a famous German student drinking song with lyrics by Johann Wolfgang von Goethe in 1811. The phrase is a combination of German and Latin. The stein is marked with part of an unidentifiable logo and "1254 Germany", ca. 1900. 
Brüderchen ergo bibamus. Brothers therefore let's drink.
Translation: Roy De Selms
Photo credit: Unknown