Origins: Wettin of Saxony
The oldest member of the House of Wettin who is known for certain is Dietrich I von Wettin, also known as Thiedericus, or as Thierry I of Liesgau (died c. 982). He was most probably based in the Liesgau (located at the western edge of the Harz). Around 1000, the family acquired Wettin Castle, after which they named themselves. Wettin Castle is located in Wettin in the Hosgau on the Saale River. Around 1030, the Wettin family received the Eastern March as a fief.
The prominence of the Wettin family in the Slavic marches caused Emperor Henry IV to invest them with the March of Meissen as a fief in 1089. The family advanced over the course of the Middle Ages: in 1263 they inherited the landgraviate of Thuringia (though 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.
Read more about this topic: House Of Wettin