I was introduced to the D&D books in 8th grade, but didn't actually play until college. Between those two times, I spent alot of time drawing maps. My father is a builder and contractor, and there were an abundance of construction plans around to draw on - 24" x 36" sheets of paper.
My first "setting" was the island of Raem. In many ways this continues to be my most successful design; 25 years later I'm still happy with the actual map, and the locations are, for the most part, unique enough to still be notable. It's one of the few maps I haven't plagarized or edited out of existence. Unfortunately, as an island I mapped out in one go, there wasn't much room for expansion.
My next effort was the north-western portion of a continent. The major feature in the area was the Shadowood Forest, and so the region was named. My ability to come up with decent names dropped to an all-time low here; I still don't know what I was thinking with "Seerlawn". And the Tiger Moors aren't bad, but the Tiger Forest and Tiger Peaks were just getting silly.
Eventually I added another sheet to the north, and at least 2 to the south - at 2' per sheet, that's 8' of map, plus eastern expansion - the maps, all together, probably achieved something like 8' x 9'. They are not often all laid out. ;)
So college came around, and a conversation with someone I barely knew led to a discussion of D&D, at which point a rather scary looking dude behind us turned around and got interested. Ten minutes later I'd been selected to DM a game I'd never even played, mostly on the basis that I had all the books.
For the past 5 years the Shadowood region had been the focus of my interest and development, so when I reached for a spot to put my first adventure, I naturally ignored it and went to nigh-totally undeveloped spot in the northernmost map, the country of Larenyss, tucked under the eaves of the Shadowend Forest. I started with "The Inheritance", from Dungeon magazine, as the adventure, but pretty swiftly went off-track. I threw the PCs back and forth across the continent, and tried to introduce some kind of meta-plot, which only marginally succeeded. Nonetheless, the PCs survived and, over the course of 4 years, went from 1st to 14th or so level, and became Important. Most of the action focused around Kestrel's Keep, but ranged.
Midway through this I started a "junior" campaign for people who hadn't been around when I started the first one; I started this one with a Dungeon adventure also (Moorwall?). The party started in Bridgeton but soon ended up in the ruins of Shalanholt. It lasted about two years (at which point I graduated), and didn't really end, but I keep the characters in mind for Positions of Importance as NPCs.
I also ran a short Faerie campaign that mingled players from the two groups, and a short campaign in a setting I called NewLands; I'm quite happy with this design also, but it never quite jelled and I ended up stopping the campaign.
Post-college begat several years of no-play, and my most prolific creative spurt - I contributed to Dragon magazine, edited the Oerth Journal, and assembled the Best of Greyhawk on AOL, a compendium of posts from the Greyhawk message boards on TSR at AOL.
Around '98 I started the Fallen campaign, my first attempt at a cohesive, quest-style campaign. I'm still pretty happy about it, but player turnover proved a problem - it's tiring to have to repeatedly give out clues because players have left. I bumped up xp and rocketed the pcs up to 12th level or so before closing the campaign - they did get to whack a number of immortal, regenerating wizards, so that was a pretty good finale! This time the action centered around the Hundred Kingdoms and north, with trips to Arthringlaur and beneath the Kameurhorns (and beyond!) to unravel the secret of exactly how to kill the Fallen.
I briefly ran a campaign set north of the Shadowend, in the Winterfall region, but folded it after 6 months; too many commitments, I think. I moved many Winterfall elements south to the Shadowend (Tuonela and the Black Sorcerers thereof; firjotun; leshii; domovii; Aesar and Vanar; the Talven Alasen) since I wanted to keep using them.
My last campaign returned to Shalanholt, and resurrected a number of features from earlier campaigns. The Fallen came back, as did "lesser" Fallen, and The Smith's Wife. This was also going to be a "quest" campaign, specifically to find the legendary Black Legion and equip the forces of Shalanholt to withstand the armies of Brindish and the sinister Black Sorcerers of Tuonela, but work, school, and life intervened once more.
Since then I've begun a real effort to detail, describe, and flesh out the Shadowend region. The timeline, such as it is, has jumped forward a hundred years - some NPCs have died, some of simply been moved forward, and some have actually had to live it (the Queen of Larenyss& Shalaen being the most notable example of this, as she dropped into Faerie and lost 60 years or so...)
Someday I'll run another campaign. Until then, I've got this blog!