- Pope Gregory IX establishes the papal Inquisition, dispatching Dominican friars to southern France to investigate heresy.
- Leonardo da Vinci begins painting the Mona Lisa.
- Hugues de Payens founds the Order of Knights Templar.
- Construction begins on the Cathedral of Notre Dame in Paris.
- Portuguese explorer Bartholomeu Dias becomes the first European to round the Cape of Good Hope, opening up a sea route to India.
- Christopher Columbus makes four voyages to America.
- Louis VI King of France and Adelaide of Maurienne are married.
- Louis VII, future King of France, is born.
- Construction of London Bridge begins.
- Prince William, heir to the English throne, drowns in the wreck of "White Ship".
- England invades and defeats France at the Battle of Agincourt, establishing England as the dominant European power.
- Michelangelo begins painting the ceiling of the Sistine Chapel.
- Owen Glendower proclaims himself Prince of Wales and begins a revolution.
- Joan of Arc is burned at the stake.
- The Treaty of Troyes is signed in an attempt to end the Hundred Years' War.
The cache would rate one-star of difficulty if hidden as a Traditional. In fact, it is not camouflaged, though it is covered by some rocks, and probably can be seen by pedestrians, but I don't believe there are many of those here.