Albert of Saxe-Wittenberg was born as the son of Otto, a younger son of the prince-elector Rudolf I of Saxe-Wittenberg, and his wife Elisabeth, daughter of Duke William II of Brunswick-Lüneburg. In 1370 he succeeded his grandfather as the Duke or Prince of Lüneburg. William II of Brunswick-Lüneburg named his grandson Albert as his heir in Lüneburg because neither he or his brother had male heirs. In fact William II had previously asked Emperor Charles IV for the eventual enfeoffment of the state to his grandson, but backed away again in the years that followed, because he feared the influence of Albert's uncles, Wenceslas I and Rudolf II. A further reason may be found in the terms of the Brunswick-Lüneburg investiture agreement of 1235 as well as the succession treaties agreed by William's father Otto the Strict with Brunswick-Lüneburg's Wolfenbüttel lineof the House of Welf, according to which the principality had to be passed to any male heir within the entire Welf house if there were one. After the death of William II and the succession of the Wolfenbüttel Magnus II, the Lüneburg War of Succession broke out between Saxe-Wittenberg and Brunswick-Wolfenbüttel. Albert was backed by his uncle the Prince-Elector Wenceslas of Saxony. On 25 July 1373, Duke Magnus was killed in a battle near Leveste on the Deister. After this an arrangement was agreed between Prince-Elector Wenceslas and Albert, on the one hand and the widow of Magnus II and her sons on the other. It was agreed that the land would belong, undivided, to the two Ascanians from Saxe-Wittenberg and, after their deaths, would be transferred to the sons of the fallen duke, Magnus II. And that it should continue to alternate after the deaths of the Welfs, i.e. the succession would pass to the Ascanians again. In order that this plan could also be reinforced by family ties, in 1374 Albert of Saxe-Lüneburg married the widow of Magnus II, Catharina and chose Celle as his home, which he made a residence in 1378. The two still underage sons of Magnus also married into the House of Ascania in 1386. He would rule the Principality of Lüneburg jointly with his uncle Wenceslas until his death on 28 June 1385.
