Who married Francis I, Holy Roman Emperor?

Francis I (Francis Stephen; French: François Étienne; German: Franz Stefan; Italian: Francesco Stefano; 8 December 1708 – 18 August 1765) was Holy Roman Emperor from 1745 to 1765, Archduke of Austria from 1740 to 1765, Duke of Lorraine and Bar from 1729 to 1737, and Grand Duke of Tuscany from 1737 to 1765. He became the ruler of the Holy Roman Empire, Austria, and Tuscany through his marriage to his second cousin Maria Theresa of Austria, daughter of Emperor Charles VI. Francis was the last non-Habsburg monarch of the Empire. The couple were the founders of the Habsburg-Lorraine dynasty, and their marriage produced sixteen children.

Francis was the oldest surviving son of Leopold, Duke of Lorraine, and the French princess Élisabeth Charlotte d'Orléans. Duke Leopold died in 1729 and was succeeded by his son. In 1736, Francis married Maria Theresa. In 1738, he left the Duchy of Lorraine and Bar for the deposed Polish king Stanisław Leszczyński in exchange for the Grand Duchy of Tuscany, as one of the terms ending the War of the Polish Succession. Following the death of his father-in-law, Charles VI, in 1740, Francis and Maria Theresa became the rulers of the Habsburg domains. Maria Theresa gave her husband responsibility for the empire's financial affairs, which he handled well. Francis died in 1765 and was succeeded by their son, Joseph II, who co-ruled Austria alongside Maria Theresa.