Prætorian Guard

Prætorian Guard, a select body of soldiers distributed in cohorts, as many as ten of a thousand each, to guard the person and maintain the power of the emperors, and who at length acquired such influence in the State as to elect and depose at will the emperors themselves, disposing at times of the imperial purple to the highest bidder, till they were in the end outnumbered and dispersed by Constantine in 312.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Prætor * Pragmatic Sanction
[wait for the fun]
Powell, Baden
Powell, Major
Powers, Hiram
Poynings's Law
Poynter, Edward John
Pozzo di Borgo, Count
Pozzuoli
P. P., Clerk of this Parish
Praed, Winthrop Mackworth
Prætor
Prætorian Guard
Pragmatic Sanction
Prague
Prairie
Prakrit
Pratique
Praxiteles
Praying-Wheels
Pre-Adamites
Precession of the Equinoxes
Précieuses Ridicules