Excellent! Thanks for that link.
What was learned
Equatorial east Africa was significantly drier than today during the Medieval Warm Period from AD 1000 to 1270, while it was relatively wet during the Little Ice Age from AD 1270 to 1850. However, this latter period was interrupted by three periods of prolonged dryness: 1390-1420, 1560-1625 and 1760-1840. These "episodes of persistent aridity," in the words of the authors, were "more severe than any recorded drought of the twentieth century." In addition, they discovered that "all three severe drought events of the past 700 years were broadly coeval with phases of high solar radiation, and the intervening periods of increased moisture were coeval with phases of low solar radiation."
(Could the sun be responsible for global warming? Nah<>)