In 2009, the Justice Department began to release reports and top-secret memos detailing interrogation techniques ... used by CIA officers against suspected terror operatives. The list of brutal techniques, including holding prisoners in small boxes, staging mock executions, and water torture, is reminiscent of some of the worst human-rights abuses on record. In medieval Europe, torture was more than just a means of punishment. Many criminal trials of the era consisted of one or more 'ordeals,' painful tests designed to prove guilt or innocence through supernatural judgment. During waterboarding, a technique first used in the 14th century, torturers begin by pumping water directly into a victim's stomach or slowly flooding his throat with liquid. Used extensively during the Spanish Inquisition, the practice became less publicly acceptable during the Enlightenment, then experienced an underground resurgence in the 19th century. Since World War II, different forms of waterboarding have been employed by governments in Japan, Cambodia, the United Kingdom and the United States, among others. In addition to performing forced labor, prisoners at Nazi concentration camps became subjects in some of the cruelest medical experiments ever performed. They were often held at extreme altitudes and temperatures to help develop new survival strategies or exposed to deadly gases and diseases in order to test vaccines. Many of these tests, directed by the infamous Josef Mengele at Auschwitz, advanced Nazi ideology by establishing 'Jewish racial inferiority.'