The Grand Duchy of Tuscany was founded in 1569. It succeeded the Duchy of Florence. The grand duchy was initially ruled by the House of Medici, until their extinction in 1737. The grand duchy passed to the House of Lorraine, and then, to its cadet branch, the House of Habsburg-Lorraine. The House of Habsburg Lorraine ruled Tuscany from 1765–1801, and then 1814–1859. A reigning grand duchess was styled:

• (1569–1691) Her Highness The Grand Duchess of Tuscany
• (1691–1737) Her Royal Highness The Most Serene Grand Duchess of Tuscany
• (1737–1765) Her Imperial Majesty Holy Roman Empress, the Queen of Hungary and Bohemia, the Archduchess of Austria, the Most Serene Grand Duchess of Tuscany, etc.
• (1765–1804) Her Royal Highness The Most Serene Grand Duchess of Tuscany, Archduchess of Austria, etc.
• (1804–1859) Her Imperial and Royal Highness The Most Serene Grand Duchess of Tuscany, Archduchess of Austria, etc.