The Harrowing of Hell is a doctrine in Christian theology referenced in the Apostles' Creed and the Athanasian Creed , which states that Jesus "descended into Hell". It has been termed the most controversial phrase in the Apostle's Creed.http://www.creeds.net/ancient/descendit.htm
Terminology
by Andrea Mantegna and studio, c. 1470]]The original Greek wording in the Apostles' Creed is , ("katelthonta eis ta katôtata"), and in Latin descendit ad inferos. The Greek ("the lowest") and the Latin inferos ("those below") may also be translated as "underworld", "netherworld", or as "abode of the dead". Thus, sometimes this phrase is translated as "descended to the dead." The first use of the English "harrowing" in this context is in homilies of Aelfric, ca.1000. Harrow is a by-form of harry, a military term meaning to "make predatory raids or incursions"OED. The term "Harrowing of Hell" refers not merely to the idea that Christ descended into Hell, as in the Creed, but to the rich traditi
Source:
http://en.wikipedia.org/wiki/Anastasis