What does SPQR mean?
SPQR is a Latin abbreviation – Senātus Populusque Rōmānus. In English ‘The Senate and People of Rome’.
The abbreviation referred to the Government of the Roman Republic. It appeared on coins but also on buildings and monuments as well as declarations and documents.
The use of SPQR on coinage began in around 80 BC when it started to replace ‘ROMA’ as part of the inscription. The use of SPQR acknowledges the legitimacy of rule and power from the people of Rome or ‘Populus Romanus’ and emphasised the freedom of the people and their combination with the Senate as the source of sovereignty. This rule of the people was as opposed to the rule by monarchy which the Roman Republic replaced and was at pains to differentiate itself from for the remainder of it’s existence. The rule of the people, as represented by ‘SPQR’ was an enduring and highly emotive concept of the freedom and unique nature of the Roman identity which was to prove so effective in coherence for so many centuries.
The end of the Republic did not end the use of SPQR as the Emperors of the Roman Empire claimed to rule in the name of the people and as their representative.
SPQR was also a very important abbreviation in the Roman military and was much in evidence. Notably the eagle or Aquila of the Roman Legion had a banner with SPQR embroidered on it. This served as reminder of the source of the power and legitimacy of the Legion and where it’s loyalty lay – that is to the people of Rome.
As the Roman world turned more and more to Christianity the SPQR abbreviation became increasingly associated with the paganism of the past. The reign of Constantine the Great 312 – 337 AD) marked the last instance that this appeared on coinage.
SPQR saw a revival in the Middle Ages and appeared on coins struck in the Commune of Rome from 1184 AD and again between 1414 and 1517 AD . Later in the nineteenth century resentful locals provided the spurious explanation for abbreviation as ‘soli preti qui rregnemo’ or “only priests reign here” . Italian dictator, Benito Mussolini also made use of the symbol in an effort to link his regime to the glory of ancient Rome.
Today when you walk the streets of Rome it is common to see the SPQR abbreviation – perhaps most noticeably on manhole covers!
 Biaggi, Elio ‘Monete e Zeche Medievalli Italiane’
 Benes, C. E ‘Whose SPQR? Sovereignty and Semiotics in Medieval Rome’