Rome

Rome was a city in Italy and the seat of a large Empire in early human history.

The Doctor visited southern Europe many times during the Roman period. He claimed to have met, among other humans native to this time, Hannibal (DW: Robot) and Cleopatra. (DW: The Masque of Mandragora) He was also familiar with the accounts of Julius Caesar and Tacitus on the customs of the Celts and their Druid priests, noting them as among the few historically reliable ones, but with no great detail. (DW: The Stones of Blood)

A group of Roman soldiers was kidnapped by the War Lords for use in their war games (DW: The War Games)

One of Scaroth's temporal splinters is known to have posed as a high-ranking Roman, possibly even an emperor. (DW: City of Death)

Around the 5th century BC, the Cult of Demnos flourished in Italy. (DW: The Masque of Mandragora)

In the year 12005, the New Roman Empire flourished. It was presumably inspired by the original Roman Empire. (DW: The End of the World)

Apocryphal references
In the native timeline of the human scientist Dr. Who, he inadvertently landed his TARDIS in the midst of a marching legion of Roman soldiers after leaving Skaro. (Dr. Who and the Daleks)

Stories set during the time of the Roman Empire

 * ST: The Last Days
 * PDA: Byzantium!
 * ST: Romans Cutaway
 * DW: The Romans
 * BFA: The Council of Nicaea
 * MA: State of Change