The Moorstag is the baronial assembly of Glenumbra, nominally composed of all the vassals of the ruling baron. Notably, it is only open to those of noble blood, excluding the entire Glenumbran commonry - and any visiting foreign emissaries found to be of common birth.

While it endeavours to encompass the whole of the Barony's plentiful aristocracy, the Moorstag has no real fixed composition. Nobles are free to attend when and as they wish, and so where one session might struggle to contain itself within the baronial castle, another could conceivably involve only the baron's own immediate retinue. Such extremes are rare, but the number of delegates fluctuates constantly depending on the issues at stake, the political climate of the realm, and even the time of year.

In accordance with its chaotic composition, the Moorstag has no fixed date in the year; its only limitation, as recorded in the most ancient codices of Glenumbra, is that one be called at least every eight months - regardless of whether there is any actual need for it. Once called, the Moorstag must go on for a week, from Sundas to Sundas, but if this tradition has been broken countless times in the past to cut the assembly short, there have only been three recorded cases of one being extended.

As many of the Glenumbran nobility are little more than petty landholders and chevalier soldier-knights, the vacuum of power left by the lack of a dominant magnate aristocracy is filled by formal alliances between delegates. Should a common goal emerge to unite several noble houses in its pursuit, they will make oaths of allegiance, and swear to stand by one another until such a time as their goals are met - or they are dead and their ashes scattered (an overly dramatic relic of a former age). Most often, such alliances do not last much longer than a single session; however, there have been cases when they lasted for months, or even years. The most recent example of such were the Grimley and Westbeth alliances, arguing respectively for and against closer ties to the Kingdom of Daggerfall.