Rudolph Dirks was responsible for the longest running newspaper comic strip in history, The Katzenjammer Kids. The strip made it's debut on December 12, 1897 and is still run in some newspapers to this very day, over 112 years!
The strip is influenced by some 19th century German woodcarvings featuring a couple of devilish young boys named Max and Moritz and the idea was presented to Dirks to do an updated version for newspapers. Dirks renamed the boys Hans and Fritz, gave them parents and a grandfather and they were dubbed the Katzenjammers. The word Katzenjammer in German translates to "the yowling of cats", and it was a slang term meaning "hangover".
As the strip grew, the father and grandfather were eventually dropped and a salty sea captain (The Captain) moved in as a border in the home and a little later a truant officer (The Inspector) came along for the boys, but after a time moved in as well.
What is truly groundbreaking about Dirks' work on the strip though, is he brought 2 conventions to the medium. Both conventions were used experimentally by other cartoonists, but Dirks made them a mainstay of his strip and for 99.9999999% of every strip to come since. The Katzenjammer Kids was the first strip to have running regular characters in it week to week, and he was the first to regularly use word balloons to have the characters speak and move the narrative along.
If that ain't enough to plant him firmly in comic strip history, I don't know what is.
Here's an early strip:
Hearst continued the strip by bringing in another artist named Harold Knerr. This cause a legal battle between Dirks and the syndicate over ownership and creator rights. The judge deemed that Dirks owned the rights to the strip and the characters therein, but that Hearst owned the name. Dirks went down the street and went to work for Joseph Pulitzer and started doing his strip there and the Katzenjammers' continued in the Hearst papers with Knerr at the helm.
At first the strip Dirks was doing didn't have a title, it just appeared under a heading saying "from the creator of the ORIGINAL Katzenjammers" and then as "Hans and Fritz".
Eventually it was named "The Captain and the Kids":
A sample of Dirks' work: