In short, it's sparsely populated and mostly rural. It produces a good deal of grain and other foodstuffs exported nearly exclusively to neighboring Vertiloch. This explains why passage and port fees exacted from foreign vessels are so high. Merchant ships laden with grain aren't exactly welcome since they compete with Theran agriculture. It is only thanks to an imperial order that Errolyn doesn't altogether block unwanted traffic on its rivers.
Theran armed forces include a proportion of cavalry higher than most other realms, more than a thousand in total. They also rely upon a hundred and fifty mid-level spellcasters and paladins, all of whom with access to pegasus mounts. A third of Theranderol's army is posted in Errolyn to face two possible threats. The capital sits on the border with Eadrin and Arogansa. Not that a war with either realms is expected anytime soon, it is best nonetheless to forestall any such temptation. Second but not least, the Great Gouge ends about thirty miles away.
Theranderol's small navy dedicates itself to protecting its sea ports and patrolling rivers. The two war galleys hail from the town of Kirn, along with two large galleys and another two smaller galleys. The two troops transports are used only if forces are urgently needed someplace else; one anchors in Errolyn, the other in Herot. The remainder patrol the Thera and Hauriant Rivers up to Bigos and Dolas. Only barges and river boats go beyond or up the Sufflue River to either Avakinel or Nehiun. The crossings at Crusilly and Sanguine are fitted with drawbridges allowing warships and merchant vessels to get through.