Did rainy climate aid Genghis Khan? Tree rings offer clues.

Scientists ask whether a period of unusual weather — suggested by ancient trees — helped the Mongol conqueror expand his power.In the rings of ancient and gnarled trees, scientists have found evidence of a period of an unusual stretch of warmth and wetness in Mongolia between the years 1211 and 1225 — the exact time that Genghis Khan was in power.
Source: Los Angeles Times - Science - Category: Science Source Type: news