Along Came Alan Moore, and The Rest is History
The real turning point, though, for Wein and the "British Invasion" came with Saga of the Swamp Thing. Wein, of course, had created the Swamp Thing with Bernie Wrightson and it was a cult classic. In 1982, a Swamp Thing film was released and DC wanted to put out a new series to tie in with the movie. So Wein put Martin Pasko and Tom Yeates on a new book called Saga of the Swamp Thing. Two years in, Wein decided to make a change, as sales were lagging on the series. He called up one of the creators that DC had met with in 1981, Alan Moore, and offered him the job. Moore was incredulous at first, but quickly accepted the gig.
As most comic book fans know, Alan Moore's approach on Swamp Thing was to come in and say, "Everything you thought you knew was wrong," revealing that instead of Alec Holland being transformed into a swamp creature in a lab accident, the explosion had instead animated a patch of the swamp into thinking that it was Alec Holland! This was revealed in a stunning sequence in Saga of the Swamp Thing #21 (by Moore, Stephen Bissette and John Totleben)...
Can you imagine being so secure with yourself as a creator that you hire a guy whose first story (after wrapping up the previous writer's story) was to pull a "Everything you thought you knew was wrong?" routine? That takes a lot of guts and confidence, but that was just the kind of man that Len Wein was.
Naturally, Saga of the Swamp Thing (later shortened to just Swamp Thing) became a critical and commercial sensation. Alan Moore became a comic book superstar and Wein was right there with him and Dave Gibbons when they then created one of the greatest comic book series ever made, Watchmen.
During the 1980s, Wein brought over more British creators, like Kevin O'Neill, but it was clearly the success of Alan Moore that led DC Comics to begin making it a point to look to England for new writers. This led to the hiring of Grant Morrison, Neil Gaiman and Jamie Delano in the late 1980s, with their Swamp Thing-esque titles, Animal Man, Sandman and Hellblazer all being classics of the genre (DC also hired John Wagner and Alan Grant to write Detective Comics in 1988, but Wagner and Grant were already well known for their Judge Dredd work, so it was not really the same thing as hiring unknowns like Morrison, Gaiman and Delano).
As the 1990s began, other British writers like Garth Ennis and Warren Ellis helped re-define the Mature Readers line of comics that had begun with Moore's Swamp Thing, with titles like Preacher and Transmetropolitan. All these types of "invasions" take is some forward-thinking people who aren't afraid of taking some risks with new talent - people like the late, great Len Wein.