The Purple Dragon was a Welsh local pub in the town of Mochdref.
In the summer of 1920, Henry Jones Sr. socialized with the locals in the pub, quoting Taliesin's verses and engaging in drinking contests hoping to entice from them Celtic legends about the Holy Grail. However, Jones got drunk, standing on the bar singing Yale college songs to a dozen attendants. He was arrested and woke the next morning in jail.