Although he was never Emperor, Henry I the Fowler, Duke of Saxony, was the founder of this imperial dynasty, since his election as German king made it possible for his son, Otto the Great to take on the imperium. Since Otto I most of the German kings were also crowned Holy Roman Emperor. Under the reign of the Ottonian rulers, the kingdom of the Eastern Franks finally became Germany as the duchies of Lorraine, Saxony, Franconia, Swabia, Thuringia and Bavaria joined in one empire. 