"Harrowing of Hell", illumination from the manuscript "Speculum humanae salvationis", ms. Harley 2838, f. 33v, between 1485 and 1509, British Library, London.
Although not officially described in any of the Gospels, the Harrowing of Hell is a pillar of Christianity; as such, it is celebrated on Holy Saturday (also known as Black Saturday). Jesus' descent into hell is, in fact, only briefly referred to in the Apostles' Creed and in later writings, such as Peter's epistles; other apocryphal writings, such as the Gospel of Nicodemus, narrate the event in much more detail. Its symbolical importance, however, has been clear from the early stages of Christianity: Christ descended to the underworld to free the souls of the just from their age-old imprisonment to the Devil. Because of this, the Harrowing of Hell has often been the subject of many illuminations. The main iconographic depiction shows Christ taking Adam and Eve by the hand, freeing them from the Gates of Hell (often represented by the mouth of the Devil himself).