The Conclave of Dukes is the de facto and de jour ruling body of Thalia. Comprised of the heads (read: Duke/Duchess) of the 6 ancestral Thalian Duchal families, the conclave is fractious, divided, and occasionally violent. The 13 non-Duchal Dukes are technically equal in rank, but do not have seats in the conclave. The conflict between the the 19 duchies of Upper Thalia has raged for millenia, yet the respective positions of the 6 and the 13 haven't changed.

The Lord Marshal of Thalia is selected from one of the six dukes/duchesses in a not-quite democratic election (often involving thousands of deaths on the battlefield).