Several sensational Grand Prix motor racing victories in 1936 and 1937 (also in the Vanderbilt Cup in the USA) made him popular not only in Germany. He won the European driving championship in 1936. Of the twelve Grand Prix contested in 1937 between Mercedes and Auto Union, Rosemeyer won four of Auto Union's five victories against Mercedes's formidable new W125. Rosemeyer's superlative performances that year cemented him alongside Rudolf Caracciola and Tazio Nuvolari as three of the greatest drivers of 1930s Grand Prix racing.