Theme: 4X, feudal system in space, the player is the emperor and there are noble houses

I look for better words for:

• “Assembly of nobles” - a kind of council of noble houses (but not parliament) with some voting rights
• “Feudal Constitution” - the feudal contract between the emperor and noble houses. Can be adjusted but it's a big deal
• “Feudal Economic Directorate” (F.E.D. :D) - a body deciding how income from fiefs, trade and so on is divided between noble houses. Each house (also the royal house of the emperor) has shares in this body and is entitled to a percentage of the income.

Could be another word for this concept, or a totally made up word, anything that sounds good, is within the theme and somehow brings the vision of the concept.

Supreme Council

The Constitution (always with a capital T on the The)

Carta Imperium

Economy Czar

Economic Council

I think simple is best. No need to use terms like “galactic” or “feudal," but “supreme” is simple and effective.