The Capital of Cardolan

[Huinesoron]

Out of curiousity I looked up Cardolan in the actual MERP sourcebooks - they're available on the Internet Archive, you can read the Arnor book here. On page 44, it describes Cardolan thus:

Originally Posted by MERP, not Tolkien

However, most of the landscape is dominated by slowly rolling, treeless grassland, a bleakness offset only by the teeming city of Tharbad, the Queen of the North.

That strongly suggests that Tharbad is the chief city of Cardolan, though it falls short of saying it's the capital. The reason for that is revealed on page 86:

Originally Posted by MERP, not Tolkien

Although Tharbad has lost all of its glitter and most of its pride, it is still a mighty city, at least by the standards of the North. The King of Cardolan once ruled Tharbad; it provided him a power base for the control of the unruly Princes. Few of the Kings had a taste for living in Tharbad, keeping to the royal compound at Thalion (Metraith). They administered the city through the office of the Mayor.

Thus, the answer to the actual MERP question asked is: there is no capital of royal Cardolan! Much like the Saxon kingdoms of England, the King lives in a royal compound/hunting lodge, separated from the chief city where the Guilds (of course they gave it guilds) are based. The King's Council is made up of provincial princes, who would stay in their own provinces; the King's Chancellor presumably either hangs out with the king or roams around. (Notably, after the fall of the kings, the council gave the Chancellor title to the captain of the Gondorian garrison at Tharbad, so maybe he hung out there.)

It may well be that the "standard line" among players is different, but the MERP source texts are clear: Cardolan has no capital, Cardolan needs no capital.

hS