Perhaps one of the more influential European strips would have to be The Adventures of TinTin. Debuting in 1929 written by Georges Prosper Remi (b. 1907 - d. 1983) under the pen name Herge, TinTin quickly became quite the success.
Essentially just an adventure strip about a plucky young journalist and his dog, the cast is rounded out by a number of wonderfully charming characters. The adventures TinTin and his dog Snowy go on usually require him to deduce the situations logically and solve numerous mysteries.
Many Americans (especially GenerationX and GenY kids) were introduced to TinTin thanks to the cartoon The Adventures of TinTin that was produced from 1991 - 1992. I remember watching this series when I was a kid and falling in love with it. It was absolutely wonderful and it's no surprise to me that TinTin was such an international sensation.
Herge wrote 23 complete adventures for TinTin, leaving a 24th unfinished, between 1929 and 1983. The unfinished book ended with a cliffhanger as TinTin was about to possibly be killed.
