The family advanced over the course of the Middle Ages: in 1263, they inherited the landgraviate of Thuringia (although without Hesse) and in 1423, they were invested with the Duchy of Saxony, centred at Wittenberg, thus becoming one of the prince-electors of the Holy Roman Empire.

Frederick III (Friedrich der Weise) appointed Martin Luther (1512) and Philipp Melanchthon (1518) to the University of Wittenberg, which he had established in 1502.

After the Battle of Mühlberg, Johann Friedrich der Großmütige, had to cede territory (including Wittenberg) and the electorship to his cousin Moritz.

Nevertheless, with Ernst der Fromme, Duke of Saxe-Gotha (1601–1675), the house gave rise to an important early-modern ruler who was ahead of his time in supporting the education of his people and in improving administration.

The Ernestine Wettins, on the other hand, repeatedly subdivided their territory, creating an intricate patchwork of small duchies and counties in Thuringia.

However, the headship of Prince Rüdiger is contested by his second cousin, Alexander (born 1954), son of Roberto Afif (later by change of name Mr Gessaphe) and Princess Maria Anna of Saxony, a sister of the childless former head of the Albertines, Maria Emanuel, Margrave of Meissen (died 2012), who had adopted his nephew and granted him the name Prince of Saxony, contrary to the rules of male descent under the Salic Law.

The senior (Ernestine) branch of the House of Wettin lost the electorship to the Albertine line in 1547, but retained its holdings in Thuringia, dividing the area into a number of smaller states.

One of the resulting Ernestine houses, known as Saxe-Coburg-Saalfeld until 1826 and as Saxe-Coburg and Gotha after that, went on to contribute kings of Belgium (from 1831) and Bulgaria (1908–1946), as well as furnishing consorts to queens regnant of Portugal (Prince Ferdinand) and the United Kingdom (Prince Albert), and the Emperor of Mexico (Carlota of Mexico)[4] Thus, the British and Portuguese thrones became possessions of persons who belonged to the House of Wettin for a time.

Severe anti-German sentiment during World War I (1914-1918) led some influential members of the British public (especially radical Republicans such as H. G. Wells[5]) to question the loyalty of the royal family.

Advisors to King George V searched for an acceptable surname for the British royal family, but Wettin was rejected as "unsuitably comic".

[6][7][8] An Order in Council legally changed the name of the British royal family to "Windsor" (originally suggested by Lord Stamfordham) in 1917.