Caligula had two large ships constructed for himself (which were recovered from the bottom of Lake Nemi around 1930). The ships were among the largest vessels in the ancient world. The smaller ship was designed as a temple dedicated to Diana. The larger ship was essentially an elaborate floating palace with marble floors and plumbing. Thirteen years after being raised, the ships were burned during an attack in the Second World War, and almost nothing remains of their hulls, though many archaeological treasures remain intact in the museum at Lake Nemi and in the Museo Nazionale Romano (Palazzo Massimo) at Rome.
In the 1934 novel I, Claudius by English Writer Robert Graves, Caligula is presented as being a murderous sociopath from his childhood, who became clinically insane early in his reign. At the age of only seven, he drove his father Germanicus to despair and death by secretly terrorising him. Graves's Caligula commits Incest with all three of his sisters and is implied to have murdered Drusilla.
In 1941, Edgar Rice Burroughs wrote I Am a Barbarian. The story is pitched as a free translation of the memoirs of Britannicus (a fictional character created by Burroughs) who was the slave of Caligula from early childhood till Caligula's death.
The character Ellsworth Toohey in Ayn Rand's 1943 novel The Fountainhead references Caligula in his climactic speech to Peter Keating stating, "Remember the Roman Emperor who said he wished humanity had a single neck so he could cut it? People have laughed at him for centuries. But we'll have the last laugh. We've accomplished what he couldn't accomplish. We've taught men to unite. This makes one neck ready for one leash."
American actor Jay Robinson famously portrayed a sinister and scene-stealing Caligula in two epic films of the 1950s, The Robe (1953) and its sequel Demetrius and the Gladiators (1954).
A feature-length historical film Caligula was completed in 1979, in which Malcolm McDowell played the lead role. The film alienated audiences with explicit sex and violence. Although reviews were overwhelmingly negative (though McDowell's performance as the title character was praised), the film is considered to be a cult classic.
Szabolcs Hajdu portrayed Caligula in the 1996 film Caligula.
The cryptoporticus (underground corridor) beneath the imperial palaces on the Palatine Hill where this event took place was discovered by archaeologists in 2008.
Details on the Mauretanian events of 39–44 are unclear. Cassius Dio wrote an entire chapter on the annexation of Mauretania by Caligula, but it is now lost. Caligula's move seemingly had a strictly personal political motive – fear and jealousy of his cousin Ptolemy – and thus the expansion may not have been prompted by pressing military or economic needs. However, the rebellion of Tacfarinas had shown how exposed Africa Proconsularis was to its west and how the Mauretanian client kings were unable to provide protection to the province, and it is thus possible that Caligula's expansion was a prudent response to potential Future threats.
The play The Reckoning of Kit and Little Boots, by Nat Cassidy, examines the lives of the Elizabethan Playwright Christopher Marlowe and Caligula, with the fictional conceit that Marlowe was working on a play about Caligula around the time of his own murder. It emphasizes the similarities between the two characters—both stabbed to death at 29, both in part as a result of their controversial religious perspectives. The play focuses on Caligula's love for his sister Drusilla and his deep-rooted loathing for Tiberius. It received its world premiere in New York City in June 2008.