Why didn't Thyatis Develop Traladara?
by James MishlerCouple things.
First, the Alphatia/Thyatis enmity and tit for tat settlement and struggle over colonies.
On the continent, the most notable of these is Alasiya (Ylaruam), which Thyatis first invaded in force in 150 AC and Alphatia followed in 250 AC. The battles in Alasiya really started in 500 AC, then heated up into full-scale war in 700 AC (presumably they were fighting more intensely during those centuries on the Isle of Dawn and elsewhere, as Alasiya would be an utter backwater, were it not literally on the doorstep of the Thyatian Heartlands).
By the mid-800's, both Alphatia and Thyatis had been thrown out of Alasiya by Al-Kalim and his forces; for some time, their continental colonial energies were spent in the Highlands, which would also eventually throw out both colonial powers later that century and form their own independent state of Glantri.
Colonial struggles between Alphatia and Thyatis then moved off continent.
Second, note that other than for reasons of power and pride, the primary reason to hold a colony is for a source of raw materials, as well as for a captive market.
One thing that the Thyatians needed after losing Alasiya and the Highlands was a source for raw materials closer to home, where the Alphatians could not interdict their merchant ships. So, with tons of raw materials in neighboring Traladara, the Thyatians invaded (also, Traladara was, like Alasiya, right on the border of the Thyatian Heartlands, so they were worried about Alphatian influence and interference, if not outright colonization).
Traladara was a hot mess of city-states, backwoods nobles, and monsters; a proper challenge for the Thyatians. And very, very rich in raw materials.
So they invaded, took hold of important choke points and markets, and generally left the interior of the land alone, as long as they got the raw materials out at a good price.
Marilenev was chosen as the capital due to its deep harbor and central position at the mouth of the greatest river system in the territory. It was renamed Specularum, which means "mirror" in the main Thyatian dialect (derived from Latin speculum, which means "mirror"). [The Real World reason "Specularum" was changed to "Mirros" in the later books is because "Specularum" sounded too much like the gynecological tool known as a "speculum;" the etymology of "mirror" for the name "Mirros" is such that its use does not make sense, as it could not refer to the "mirror-like" quality of the bay unless they were speaking English].
And then for 70 years, the Thyatians were happy to have a local colony that generated raw materials and acted as a market for their finished goods (exclusive market, or in some cases, other merchants from elsewhere were allowed to trade there, but with high tariffs). It also opened up trade overland with Darokin after the Great Merger.
It was also a good dumping ground for Thyatian criminals, used as slave labor on the plantations on the coastal farmlands and inland in the lumber camps (another reason Traladarans have a bad opinion of Thyatians). It was also a good training ground for the legions, as the goblins of the Dymrak were numberless, but no serious threat outside of their forest.
But the Thyatians had no intention of ever developing Traladara; developed colonies are nothing but trouble, as the locals often then demand fewer taxes, more freedom, greater power, and eventually, independence! And so Traladara was left as nothing more than a raw-material extraction colony. Of course it still grew, with colonists both willing and otherwise from Thyatis, and with the need for more workers to extract more raw materials. And so Specularum grew from 5,000 to 50,000, and new towns grew from old villages.
Then came the Alphatian Spike and near conquest of Thyatis in 960, and the subsequent economic crash and near chaos. Long-term investments like Traladara were no longer an issue, as Thincol needed cash, now! So he sold Traladara off to Stefan, and the rest is history...