Warren Chase credits the Mongols for introducing gunpowder and its associated weaponry into Europe. A later legend arose in Europe about a mysterious Berthold Schwarz who is credited with the invention of gunpowder by 15th- through 19th-century European literature. End of the Mongol advance During 1241, most of the Mongol forces were resting on the Hungarian Plain. In late March 1242, they began to withdraw. The most common reason given for this withdrawal is the Great Khan Ögedei's death on December 11, 1241. Ögedei Khan died at the age of fifty-six after a binge of drinking during a hunting trip, which forced most of the Mongolian army to retreat back to Mongolia so that the princes of the blood could be present for the election of a new great khan. This is attested to by one primary source: the chronicle of Giovanni da Pian del Carpine, who after visiting the Mongol court, stated that the Mongols withdrew for this reason; he further stated that God had caused the Great Khan's death to protect Latin Christendom. As Stephen Pow pointed out in his analysis of this issue, by Carpini's account, a messenger would have to be able to make the journey from Mongolia to Central Europe in a little over three months at a minimum; the messenger would have to arrive in March, meaning he took about three months in the middle of winter from the time of the khan's death. Carpini himself accompanied a Mongol party in a much shorter journey (from Kiev to Mongolia) in 1246, where the party "made great speed" in order to reach the election ceremony in time, and made use of several horses per person while riding nearly all day and night. It took five months. Rashid Al-Din, a historian of the Mongol Ilkhanate, explicitly states in the Ilkhanate's official histories that the Mongols were not even aware of Ogedei's death when they began their withdrawal. Rashid Al-Din, writing under the auspices of the Mongol Empire, had access to the official Mongol chronicle when compiling his history (Altan Debter). John Andrew Boyle asserts, based on the orthography, that Rashid Al-Din's account of the withdrawal from central Europe was taken verbatim from Mongolian records. Another theory is that weather data preserved in tree rings points to a series of warm, dry summers in the region until 1242. When temperatures dropped and rainfall increased, the local climate