English: Principia or administrative block of the Hardknott Roman Fort. The principia was set at the centre of the fort. It consisted of a covered walkway around three sides of an open atrium (courtyard) and a hall on the fourth side. The tribunalis (tribunal) is a raised dais from which the commanding officer would give orders for the day, lead assemblies and so on. The aedes (shrine) where the units standards were kept was off the hall. The two remaining rooms were probably used for administration purposes. The main gate of the principia opened onto the via praetoria which led to the porta praetoria (main gate).