It has been told traditionally that the Gion festival was originated from the ritual in 869. Epidemic disease occurred in Kyoto at that time and many people suffered. The administration erected 66, which represents the number of provinces that existed in that era, spears to invoke the gods rooted in Gion and prayed for eliminating the disease.
source: the Kyoto newspaper online.
If this is true, it's been more than a thousand years. We can call this one of the historical events in Japan. I believe no one would argue that.