| Ernest Augustus II | |
| Full Name: | |
| Reign: | 1748 - 1758 |
| Succession: | Duke of Saxe-Weimar |
| Predecessor: | Ernest Augustus I |
| Regent: | Duke Francis Josias Duke Frederick III |
| Successor: | Charles Augustus |
| Reign1: | 1748-1758 |
| Succession1: | Duke of Saxe-Eisenach |
| Predecessor1: | Ernest Augustus I |
| Regent1: | Duke Francis Josias |
| Successor1: | Charles Augustus |
| Issue: | |
| House: | House of Saxe-Weimar-Eisenach |
| Father: | Ernst August I, Duke of Saxe-Weimar |
| Mother: | Margravine Sophie Charlotte of Brandenburg-Bayreuth |
| Birth Date: | 2 June 1737 |
| Birth Place: | Weimar |
| Death Place: | Weimar |
Ernst August II Konstantin, Duke of Saxe-Weimar-Eisenach (2 June 1737 - 28 May 1758), was the reigning Duke of Saxe-Weimar-Eisenach.
He was the second (fifth in order of birth) but eldest and only surviving son of Ernst August I, Duke of Saxe-Weimar by his second marriage to Margravine Sophie Charlotte of Brandenburg-Bayreuth, eldest daughter of Georg Friedrich Karl, Margrave of Brandenburg-Bayreuth.
Ernst August II Konstantin's father, a splendor-loving ruler with a passion for hunting, had moved his court to Eisenach. The duke neglected his son and heir, so that Ernst August II Konstantin spent his early years under the supervision of the Hofmarschall of Schloss Belvedere in Weimar.
Ernst August I died in 1748, when Ernst August II Konstantin was eleven years old. Since he was still a minor, the dukes Frederick III of Saxe-Gotha-Altenburg and Franz Josias of Saxe-Coburg-Saalfeld assumed the regency of Saxe-Weimar-Eisenach on Ernst August II Konstantin's behalf. The young duke came to live with Duke Frederick in Gotha, who made sure that Ernst August II Konstantin received an appropriate education.
In 1755 Ernst August II Konstantin assumed the reins of government. He appointed his former tutor, the Imperial Count (Reichsgräf) Heinrich von Bünau, as his new chancellor. Because the young duke had been a sickly child, he was encouraged to marry quickly in order to ensure an heir for the duchy. The bride was chosen from the House of Welf, in particular, from reigning family of the Duchy of Brunswick, which was blood related to almost all European ruling families.
In Brunswick on 16 March 1756, Ernst August II Konstantin married Anna Amalia of Brunswick-Wolfenbüttel, the third surviving child and second daughter of Charles I, Duke of Brunswick-Wolfenbüttel and his wife, Princess Philippine Charlotte of Prussia, sister of Frederick the Great. The marriage produced two sons:
Ernst Augustus II Konstantin passed away on 28 May 1758 in Weimar. When he died, the hereditary prince Karl August was still an infant. Ernst August Konstantin's widow, the Duchess Anna Amalia, presided as regent over an excellent tutelary government which propelled Weimar into the classical period, most prosperous period of the country. He was buried in the Palace Church of Schloss Weimar, but in 1825, his grave was transferred to the Ducal Vault in the Historic Cemetery, Weimar.[1]
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