Also known as Temple of the Deified Julius Caesar (Tempio del Divo Giulio) or Temple of the Comet Star. Historically it was also called delubrum (a shrine that housed the image of a deus, "god") and heroon (shrine dedicated to an ancient Greek or Roman hero), referring to its function in the cultic reverence of Caesar. It's remains are located among some of the most notable structures, including Regia, Temple of Vesta, Temple of the Dioscuri, Forum Square, Basilica Aemilia and Temple of Antoninus and Faustina.

The Aedes Divi Iuli was collectively decreed by the triumvirs Octavian, Antony and Lepidus in 42 BCE after the senate deified Julius Caesar posthumously. However, as the political dynamics shifted among Octavius, Antony and Lepidus, the temple was completed by Octavian alone. He dedicated the prostyle temple (it is still unknown whether its order was Ionic, Corinthian or composite) to Caesar, his adoptive father, on 18 August 29 BCE, as part of the triple triumph celebrating his victory over Antony and Cleopatra. Built on the site of Caesar's cremation, it is surrounded by a number of notable structures, situated on the east side of the main square of the Roman Forum, between the Regia, Temple of Castor and Pollux, and the Basilica Aemilia.

Although the Temple of Caesar was most likely depicted on the Forma Urbis Romae, the fragment depicting it is lost.

circa 44 BCE

The Temple of Divus Iulius was constructed in the Roman Forum on the site where Julius Caesar was cremated following his assassination in 44 BCE. Commissioned by Augustus in 42 BCE, after the Senate officially deified Caesar, the temple served both religious and political purposes. Its dedication in 29 BCE, shortly after Augustus' victory at Actium, reinforced the divine status of Caesar and legitimized Augustus’ own rule. The temple stood on a high podium with a rostra at its front, from which public speeches were given, and its façade was adorned with a star symbolizing the comet seen after Caesar’s death—interpreted as his soul ascending to the heavens. Ancient coins suggest the temple featured either Ionic or Corinthian columns, but later excavations found Corinthian pilaster capitals, indicating a possible mix of styles.

The temple’s altar, originally placed in front of the podium, was a focal point of early public worship but was later removed, possibly due to changing religious attitudes. Inside, a colossal statue of Julius Caesar, veiled as Pontifex Maximus and holding an augural staff, stood as the centerpiece of devotion. The temple also housed significant artworks, including paintings by Apelles, one of which depicted Venus Anadyomene. Over time, the structure underwent modifications, notably during the reign of Septimius Severus, when it was restored after a fire. Eventually, as Christianity took hold in Rome, the temple’s significance declined, and its materials were repurposed. Today, only fragments of its podium and some architectural elements remain, standing as a testament to Caesar’s enduring legacy.

circa 44 BCE

Exterior
The Temple of Caesar stood on a high podium measuring approximately 27 by 30 meters, constructed primarily from tuff, travertine, and marble. Its exact column arrangement remains uncertain, with possibilities including prostyle or peripteral configurations. Ancient coins suggest the use of Ionic or composite columns, but archaeological evidence leans toward Corinthian. The temple’s front featured a pycnostyle porch with closely spaced columns, and its entablature included modillions and floral decorations. Over time, restorations under Septimius Severus may have altered its original design. The staircase arrangement remains debated, with theories suggesting it could have been positioned at the front or rear. A prominent feature of the temple’s exterior was the Rostra ad Divi Iuli, a speaker’s platform adorned with the prows of captured warships, likely used for imperial orations and civic addresses.

Altar
At the temple's forefront, an altar (inspect) set in a semicircular niche, were originally integral elements, commemorating the site of Julius Caesar's cremation. These features were clearly present during the temple's dedication in 29 BCE, as depicted on Augustan-era coinage. However, at some point later, either during Empire period or much later in the Christian period—the altar and the niche were walled off, likely due to evolving religious attitudes. Some scholars suggest that rather than being the altar of Caesar, this structure could have been the Puteal Libonis, a sacred site linked to judicial oaths. Despite these uncertainties, the altar’s original presence reinforced the temple’s function as a focal point of Caesar’s deification, visually emphasizing his divine status.

Interior
The interior of the temple was richly adorned, featuring a colossal statue of Julius Caesar, veiled as Pontifex Maximus, with a star atop his head and an augural staff in his hand. Positioned to be visible from the Forum when the temple doors were open, this statue reinforced the emperor’s deified status. The temple’s cella housed celebrated artworks, including a renowned painting of Venus Anadyomene by Apelles, which deteriorated during Nero’s reign and was later replaced by another artwork. Additional paintings, such as one depicting the Dioscuri with Victoria, further adorned the space. The temple served not only as a place of worship but also as a political and ideological monument, with Augustus using it to dedicate war spoils, solidifying its role in the imperial cult.