Explanation: The Praetorian Guard was a unit of troops in the Roman Empire whose stated purpose was to protect the Emperor. Oftentimes they're thought of as an elite military force, but in reality they were more of a secret police, though they could be forced into the field on occasion, with mixed results. They were known as the "Toga'd unit" ( cohors togata ) because they spent most of their time in togas, the equivalent of formal wear; all the better to surreptitiously spy on Senators and be ready to discreetly cut throats at a banquet.
Most notable, however, is how utterly shit they were at their job. The Praetorian Guard has a history as long as the history of the Praetorian Guard of conspiring against the ruling Emperor, and sometimes couping and replacing him. What a troublesome lot!