SPQR-Who

SPQR is an initialism for the Latin phrase "the Senate and People of Rome." It refers to the government of the ancient Roman Republic. It was used as the official signature of the government. It appears on coins, documents made public by inscription in stone or metal, in dedications of monuments and public works, and was emblazoned on the standards of the Roman Legions. The phrase also appears many times in Roman literature.

Link: http://www.novaroma.org/vici/images/thumb/400px-Spqr-big-trans.gif