The Battle of Carrhae (Latin pronunciation: [karrae]) was fought in 53 BC between the Roman Republic and the Parthian Empire near the ancient town of Carrhae (present-day Harran, Turkey). An invading force of seven legions of Roman heavy infantry under Marcus Licinius Crassus was lured into the desert and decisively defeated by a mixed cavalry army of heavy cataphracts and light horse archers led by the Parthian general Surena. On such flat terrain, the Legion proved to have no viable tactics against the highly-mobile Parthian horsemen, and the slow and vulnerable Roman formations were surrounded, exhausted by constant attacks, and eventually crushed. Crassus was killed along with the majority of his army. It is commonly seen as one of the earliest and most important battles between the Roman and Parthian Empires and one of the most crushing defeats in Roman history. According to the poet Ovid in Book 6 of his poem Fasti, the battle occurred on the 9th day of June.

Crassus, a member of the First Triumvirate and the wealthiest man in Rome, had been enticed by the prospect of military glory and riches and decided to invade Parthia without the official consent of the Senate. Rejecting an offer from the Armenian King Artavasdes II to allow Crassus to invade Parthia via Armenia, Crassus marched his army directly through the deserts of Mesopotamia. His forces clashed with Surena's troops near Carrhae. Surena's cavalry killed or captured most of the Roman soldiers. Crassus himself was killed when truce negotiations turned violent.

His death ended the First Triumvirate. The following four-year period of peace between the remaining two members of the Triumvirate, Julius Caesar and Pompey, argues against the view that Crassus had been a peacekeeper within the group and supports the views of most Roman historians that friction between Crassus and Pompey had always been a greater cause of tension than that between Caesar and Pompey.

Ludi (Latin plural) were public games held for the benefit and entertainment of the Roman people (populus Romanus). Ludi were held in conjunction with, or sometimes as the major feature of, Roman religious festivals, and were also presented as part of the cult of state.

The earliest ludi were horse races in the circus (ludi circenses). Animal exhibitions with mock hunts (venationes) and theatrical performances (ludi scaenici) also became part of the festivals.Days on which ludi were held were public holidays, and no business could be conducted—"remarkably," it has been noted, "considering that in the Imperial era more than 135 days might be spent at these entertainments" during the year. Although their entertainment value may have overshadowed religious sentiment at any given moment, even in late antiquity the ludi were understood as part of the worship of the traditional gods, and the Church Fathers thus advised Christians not to participate in the festivities.The singular form ludus, "game, sport" or "play" has several meanings in Latin. The plural is used for "games" in a sense analogous to the Greek festivals of games, such as the Panhellenic Games. The late-antique scholar Isidore of Seville, however, classifies the forms of ludus as gymnicus ("athletic"), circensis ("held in the circus," mainly the chariot races), gladiatorius ("gladiatorial") and scaenicus ("theatrical"). The relation of gladiatorial games to the ludi is complex; see Gladiator.