The Maria Theresa thaler (MTT) is a silver bullion coin and a type of Conventionsthaler that has been used in world trade continuously since it was first minted in 1741.
On 19 September 1857, Emperor Francis Joseph of Austria declared the Maria Theresa thaler to be an official trade coinage.
Being of similar size to the Spanish eight-real coin, and initially thought to be of French origin, the MTT acquired the Arab name al-riyal al-fransi (الريال الفرنسى, literally the 'French riyal').
It is an abbreviation of Maria Theresia, Dei Gratia Romanorum Imperatrix, Hungariae Bohemiaeque Regina, Archidux Austriae, Dux Burgundiae, Comes Tyrolis.
1780 ☓, which means, 'Maria Theresa, by the grace of God, Empress of the Romans, Queen of Hungary and Bohemia, Archduchess of Austria, Duchess of Burgundy, Countess of Tyrol.
In 1961 the 25-year concession ended and Austria made diplomatic approaches to the relevant governments requesting they cease production of the coin.
It was common from North Africa to Somalia, Ethiopia, Kenya, down the coast of Tanzania to Mozambique, and also in the Arabian Peninsula (Oman, Yemen).
The Italian government produced a similarly designed coin in the hope of replacing the Maria Theresa thaler, but it never gained acceptance.
[6] The Maria Theresa thaler was also formerly the currency of the Hejaz, Yemen, and the Aden Protectorate, as well as Muscat and Oman on the Arabia peninsula.
[8] In the United Kingdom, the Maria Theresa thaler bearing the date of 1780 is a "protected coin" for of Part II of the Forgery and Counterfeiting Act 1981.
[11] In 1868, the British military expedition to Magdala, the capital of Emperor Tewodros II of Ethiopia, under Field Marshal Robert Napier, took MTTs with them to pay local expenses.
Then during World War II, the British minted some 18 million MTTs in Bombay to use in their East African Campaign to drive the Italians out of Ethiopia.