The present-day Pantheon is located on the site of an earlier structure of the same name, constructed around 25 B.C. by statesman Marcus Agrippa, son-in-law of the first Roman emperor, Augustus.
Traditionally thought to have been designed as a temple for Roman gods, the structure’s name is derived from the Greek words pan, meaning “all,” and theos, meaning “gods.”
The original Pantheon was destroyed in a fire around 80 A.D. It was rebuilt by Emperor Domitian, only to be burned down again in 110 A.D.
Hadrian became emperor in 117, a time when the Roman Empire included much of present-day Europe, as well as parts of the Middle East and northern Africa. Passionate about art and architecture, he embarked on a building campaign during his reign, which lasted until his death in 138.
Among these building projects was a defensive fortification, now referred to as Hadrian’s Wall, marking the northwest frontier of the Roman Empire. The wall measures 73 miles in length and stretches from coast to coast across modern-day northern England.
It’s unknown who the existing Pantheon’s architect was or exactly what role Hadrian played in the project. Evidence suggests the Pantheon was dedicated around 126-128 A.D., although construction might have started under Hadrian’s predecessor, Trajan, who served as emperor from 98 to 117.
It’s uncertain why, but Hadrian put Agrippa’s original inscription on the new Pantheon—“Marcus Agrippa the son of Lucius, three times consul, made this”—which led to centuries of years of confusion about its origins.
No one knows the original purpose of the present-day Pantheon, but Hadrian sometimes held court there.