23.2 mm, 3.22 gram
Emperor Le Hy Tong ruled for 29 years then relinquished the throne to Prince Duy Duong. Lord Trinh Can enthroned Duy Duong as Emperor Le Du Tong in 1706. Vinh Thinh (1705-1719) was the first reign title, before Bao Thai (1720-1729), of the King. Under his rule, Viet had a period of relative prosperity and peace. In 1729, Lord An Do Vuong Trinh Cuong coerced Emperor Du Tong to yield Prince Duy Phuong the throne.
Based on coins found in Vietnam, Vinh Thinh coins were in copper and had several varieties. The reverse side of coins were different, some with plain reverse side, some with the character Ty (cast in the year Quy Ty 1713) or some with the character Ky (cast in the year Ky Suu 1709). In the book Catalogue des monnaies vietnamiennes by Francoise Thierry, he showed a large coin with the character Ky on the reverse side. The coin was the first large Annam coin with its diameter 50.5 mm. According to Thierry, this large coin cast to celebrate Lord Trinh Cuong succeeded Lord Trinh Can as the ruler of Tonkin in the year Ky Suu 1709.