Riordan Wiki

The Principia is the headquarters for the Praetors located in Camp Jupiter. The Praetors meet at the principia to discuss important matters.


The principia is a two-story wedge of white marble with a columned portico like an old-fashioned bank with Roman guards standing out in front of it. Over the doorway, hangs a big purple banner with the gold letters SPQR embroidered inside a laurel wreath. Inside, on the ceiling glitters a mosaic of Romulus and Remus under Lupa. The floor is polished marble. The walls are draped in velvet, making it feel like being inside the world’s most expensive camping tent. Along the back wall stands a display of banners and wooden poles studded with bronze medals, military symbols, Percy guessed. In the center was one empty display stand for the eagle standard. In the back corner, a stairwell leads down and is blocked by a row of iron bars like a prison door. In the center of the room, a long wooden table was cluttered with scrolls, notebooks, tablet computers, daggers, and a large bowl filled with jelly beans. Behind the table, there are two high-backed chairs meant for the Praetors.

The Heroes of Olympus

The Son of Neptune

Reyna, Percy, and Hazel talked in the principia to find out more information about Percy and what he remembers.

The Trials of Apollo

The Tyrant's Tomb

Apollo and Meg McCaffrey meet with Frank and Reyna to discuss tactics to defend the valley from the oncoming attack by Triumvirate Holdings and how to perform the Ceremony to Call for Divine Help.


Camp Jupiter
Camp Jupiter: Bathhouse | Bombilo's Coffee Shop | Camp Borders | Camp Jupiter Aviary | Camp Jupiter Stables | Circus Maximus | Cohorts | Coliseum | Cyclops Books | Field of Mars | Garden of Bacchus | Little Tiber | New Rome | New Rome University | Mess Hall | Neptune's Shrine | Pluto's Shrine | Praetorium | Principia | Senate House | Temple Hill | Temple of Bellona | Temple of Diana | Temple of Jupiter Optimus Maximus | Temple of Mars | Temple of Mercury | Via Praetoria | Via Principalis