The good folk at Wikipedia tell us that it was on this day in 1784 that the famed Emerald Buddha was moved to its permanent (well as permanent as anything can be) location at the Wat Phra Kaew, in Bangkok.
The Buddha image has blended religious symbolism with that of the state, and is considered a palladium, the sacred protective image of Thai society in a manner similar to Athena’s relationship to ancient Athens, or the image of the Theotokos of Vladimir, now called Moscow to that city.