Originally belonging to Apollodorus, a loyal friend and follower of Cleopatra, he gave it to Aya, who was being pursued by Gennadios, the Phylakitai of the city after she assassinated Actaeon and Ktesos in 48 BCE. Aya sought refuge in the hideout until her husband Bayek was able to assassinate Gennadios, allowing her to roam freely in Alexandria again.
A year later, when the Order of the Ancients manipulated Julius Caesar to spare Lucius Septimius and Cleopatra to release Aya and Bayek from her services, they formed the Hidden Ones and established the Den as their temporary base of operations. While Bayek hunted down Flavius Metellus, Aya made plans to travel to Rome to eliminate Septimius. Recruiting the Roman senators Marcus Junius Brutus and Gaius Cassius Longinus, they made preparations using the den before leaving.