LORD OF THE ISLES was my chance to get back to writing fantasy. It now seems an obvious thing to have done, but it sure took me a long time to come to that realization.
Andrew Lang's Color Fairy Books were a staple of my reading as a child, and when I entered my teens and could buy books for myself I was just as interested in fantasy as science fiction. Robert E Howard's heroic fantasy stories were a lot of the reason I started writing myself, and when I was seventeen I read The Lord of the Rings for the first time. (I've reread the work frequently).
It's my belief that heroic fantasy forms a broad arc, with Howard being one pole and Tolkien the other. The works of the two men differ in emphasis but are extremely similar at the core level. Both writers affected me and my writing a great deal.
For my first fifteen years of writing, I sold as much fantasy (generally heroic fantasy, but some modern horror as well) as I did SF. My first novel, a heroic fantasy, came out a few months after my first book, a linked collection of military SF.
The latter, Hammer's Slammers, helped to create the genre of modern military SF. The novel, The Dragon Lord, wasn't an embarrassment but it sure didn't set the world on fire. Publishers asked me for more military SF, and I obliged. Military SF was never the majority of what I wrote, but it remained the thing I was known for and the thing that publishers wanted from me.
Occasionally I wrote a fantasy, because I like fantasy. None of them sold particularly well (and indeed, I didn't expect Old Nathan to sell. I wrote the book as homage to my late friend Manly Wade Wellman, and Jim Baen--bless his kindly heart--published it as a favor to me.)
Then came a contraction of the SF market generally and of military SF in particular. The latter had been so hot a genre that quite a number of opportunists had gotten into it despite their lack of knowledge of the military and/or skill at writing.
I'd seen this coming (the downsizing of the US military had by itself removed millions of potential readers from barracks where they had a great deal of time on their hands), but I couldn't get anybody to listen to me. I got very frustrated that even when I wrote books that weren't military SF, the covers and blurbs told readers that they were military. (See the discussion on Northworld for an extreme example.)
It occurred to me that I could write a heroic fantasy, this time slanting it toward the Tolkien end of the spectrum instead of the Howard end as I had with The Dragon Lord. That portion of the market seemed to be holding up well (unlike Adventure SF), and my editor at Tor was Robert Jordan's editor (and wife).
I discussed my plan with Tom Doherty, Tor's publisher. He thought it was a great idea but suggested one change: I'd intended to use Atlantis as a setting. Tom pointed out that none of the series which had done really well had real-world settings; and OK, Atlantis wasn't exactly real, but--
I don't generally argue with a publisher, especially when (as in this case) he's one of the best marketing people in the business. I set my novel in The Isles, which are Not Atlantis.
The research for Lord of the Isles was wonderful fun. I based the religion on that of Sumer--for the heck of it, no real reason except that I had the background to do it and most people wouldn't. It's not as well known as, say, the Celtic milieu. I based the culture of the Isles more or less on that of medieval and early modern England, but with a heavy admixture of the Classical Mediterranean.
I owe a particular debt to Clark Ashton Smith, whose fantasy stories I find extremely effective. Smith is best known for his florid language, but in truth he didn't have a good grasp of the words he used. (For somebody who fully understood his wide vocabulary, read ER Eddison.) Where Smith shines (for me) is in the vividness and inhumanity of his conceptions. Many of scenes in the Isles series are stolen from or at least suggested by Smith's stories.
Having said that, the tone of the Isles series and of all my work differs greatly from that of Smith's fatalism. My characters always try, though sometimes they die trying.
Lord of the Isles was by far the longest book I'd written to that point, but it wasn't unusually complex for me. The Jungle, though only a short novel, used three viewpoints and two interlocking timelines. Let me tell you, that was complex. Likewise the Northworld novels, an SF series set in a fantasy milieu in which time itself was one of nine variables, were extremely complex. The interwoven viewpoints in Lord of the Isles were braided in a relatively simple fashion.
I've always worked to make every story and novel self-standing, whether or not it's in series. Lord of the Isles had to have its own beginning, middle and end. It does and so do each of the later volumes in the series. This isn't anything new: I've done the same with the Hammer series over a run stretching back to 1973.
Tor pushed Lord of the Isles hard and effectively. I'm delighted, not only because it's always nice to have something that works but because the success broadens the range of what I'm permitted to do. I don't want to write only heroic fantasy, but I love the genre and it does my soul good to be able to write it part of the time.