In 1291 there was a further division of the estate as a resolution of the inheritance dispute between the brothers: Henry was given the Principality of Grubenhagen; Albert took over the Principality of Göttingen and William was given the territories around Brunswick-Wolfenbüttel. When William died in 1292, a disagreement broke out over who should inherit. In the end Henry withdrew to Grubenhagen leaving Brunswick-Wolfenbüttel to Albert.
After the death of Albert his sons Otto the Mild, Ernest and Magnus divided the princedom. After Otto died without issue in 1344, his two brothers Ernest and Magnus divided the estate between them: Ernest received the Land of Oberwald with Göttingen, whilst Magnus the Pious took over the reins of power in Brunswick-Wolfenbüttel.
Henry the Younger (1489–1568); - under him the medieval fortress (Burg) was rebuilt into a castle (Schloss); he was a passionate opponent of the Lutherans, and driving force behind the Catholic alliance established against the Schmalkaldic League; the disinheritance of a third son could not be carried out
Julius (1528–1589); - a great builder of the town, who from the fortress created the first systematically laid out Renaissance town; in 1572 he founded the library, whose present name goes back to its most important collect, Duke August the Younger; he also founded the university in Helmstedt in 1576 and built the castle of Hessen; in the early 16th centurh he reinforced the bastions into a fortress; he purchased Kalenberg, Göttingen and Diepholz; Julius was a Protestant
Rudolf Augustus (1627–1704) according to reports dating to 1677, he slashed a way through the Lechlum Forest, the Alten Weg ("Old Way"), later the "Barock Road" between the Lustschloss of Antoinettenruh via the little barock castle [later the Sternhaus] to the Großes Weghaus at Stöckheim; in 1671 he captured the town and fortress of Brunswick
Anthony Ulrich (1633–1714) - Anton Ulrich was a politician, art lover and poet; founder of the museum named after him in Brunswick; er had Salzdahlum Castle built
Charles I (1713–1780) - founder of the Collegium Carolinum in Brunswick, the porcelain makers of Fürstenberg, the fire office; in 1753 the Residence was moved to Brunswick
Charles II William Ferdinand (1735–1806) - he was the head of the Prussian Army; died in the Battle of Jena; because his son and heir died young, and two other sons were not eligible, rule passed to his youngest son:
Wilhelm Havemann: Geschichte der Lande Braunschweig und Lüneburg. 3 Bände. Nachdruck. Hirschheydt, Hanover 1974/75, ISBN 3-7777-0843-7 (Originalausgabe: Verlag der Dietrich'schen Buchhandlung, Göttingen 1853-1857, online near Google Books)
Hans Patze (Begr.): Geschichte Niedersachsen. 7 Bände. Hahnsche Buchhandlung, Hanover 1977- (Veröffentlichungen der Historischen Kommission für Niedersachsen und Bremen, 36) (Übersicht des Verlags)
Gudrun Pischke: The Landesteilungen der Welfen im Mittelalter. Lax, Hildesheim 1987, ISBN 3-7848-3654-2