He also wrote a good deal of heroic fantasy/swords and sorcery long before it was fashionable to do so. His character, Elak of Atlantis, may have been a forerunner of Elric of Melnibone; the two heroes have quite a bit in common.
Kuttner wrote prodigiously for the pulps during the forties, under his own name and a multitude of pen names. He also managed to marry Catherine Lucille Moore, and the two often collaborated on stories. One odd thing is that stories written with Kuttner's byline paid more than those written with Moore's. Though they often collaborated, as in the book shown below, there are some stories that were completely written by Catherine, but they have Henry's name on them. However, no one now knows what the titles of those stories were.
Even ten years after he was dead, cheap science fiction publishers were still sneaking his stuff back into print. Do you suppose it is just a coincidence that The Creature from Beyond Infinity, originally published in a pulp magazine in 1940, should reappear as a cheap paperback from Popular Library, exactly 28 years after its original publication when the copyright ran out?
Kuttner set the best of his science fiction and fantasy in timeless places well beyond the bounds of the mundane 20th century, and so it holds up pretty well, and does not seem dated when we read it now almost 60 years after it was written.
If I could have been a SF writer in the thirties and forties, I would have liked to have been Henry Kuttner!