Maria Theresa Thaler
Maria Theresa, also called Maria Theresia, was born May 13th 1717, and died on November 29th 1780. She succeeded to the throne of the Hapsburg empire in 1740, and her titles include Queen of Hungary and Bohemia, Archduchess of Austria, Empress of the Holy Roman Empire.
After her death, silver thalers were issued with the dual purpose of being a 'trade' coinage, and a commemorative. It is unlikely that any were issued in the year 1780 itself, but have been issued ever since bearing the date of her death.
The Maria Theresa thaler has often been described as the world's most beautiful coin