20 March, 1736 – the Birthday of the First King of Chakri Dynasty
His Majesty King Phra Phutthayotfa Chulalok Maharat or King Rama I was the first Thai monarch in the Chakri dynasty. He crowned as the first King of Rattanakosin on April 6th, 1782 when he was 46 year old. After his accession, he moved the capital from Thonburi to Phra Nakhon where was the city of Bangkok and his Grand Palace was construct after that.