Hi, all. TIA for any help!
I started playing III about 3 weeks ago. I have been playing on Chieftain level with sedentary barbarians and usually win either by cultural domination or on points. (I know, I know, you're really impressed, right?

) Yesterday, after winning a Regent level game that I downloaded (it was an SG) and played from about 150 BC, I decided to try Warlord level. Large map, 5 other civs.
I can already tell that I'm probably not going to win it. I'm always behind on tech so I doubt I can win the SR, and all of the other civs have a lot more territory than I do. Is there a trick or tip or strategy for early expansion? The CPs are worse than Oklahoma Sooners - they are horning in anywhere there's a free couple of tiles, stealing my resource colonies by plopping cities down next to them, and running rampant through my territory building roads and looking for any spare bit of terrain they can use to build a city. I
thought the "territory" concept in III would keep them out, that I could build a "ring" of outer cities and expand towards the center, but they go right through my territory and build cities betwixt and between, ignoring my repeated demands to get out of my territory even though they
say they will comply (along with some gratituitous insult like "were I as weak as you, I'd feel threatened too).
Also, by the time I had 3 or 4 cities going and really started cranking out settlers, they were encroaching all around me and I barely got enough turf to even be a player. How do they do it? I usually build a defensive unit first, then a temple (to expand city size to normal and help w/happiness). By then if I've located the city in what I consider to be desirable terrain, it's usually at least size 3 or 4 and I build a settler. Then I go back and build a granary or marketplace or something to let it grow again, and then build another settler (if there's any place left to send it to!!).
Then every time a city gets to its max size (6 or 12), I build a settler every time it finishes another project. There is usually one city that is placed for high shield output, developed early, and never used to produce settlers which is the city I use to build wonders in, and I am trying to learn to use the concept of a designated "science" city that decreases how long it takes to research techs.
Obviously I am not expanding nearly fast enough, as I am seriously outpaced by all of the CPs. If all you do is crank out settlers and build more cities early in the game, though, how do you ever get anything else built?? Seems like all of your cities would remain very small (because they keep losing pop to settlers) and you would have very low production of everything!
Obviously that's not entirely the case since the CPs still manage to research tech and build wonders faster than me, but I can't figure out how they do it!!
Heike