Albert the Tall (Latin: Albertus Longus, German: Albrecht der Große; 1236 – 15 August 1279), a member of the House of Welf, was Duke of Brunswick-Lüneburg from 1252 and the first ruler of the newly created Principality of Brunswick-Wolfenbüttel from 1269 until his death.
[2] Albert's rule was initially troubled by several armed conflicts as the Welf dukes still had to cope with the followers of the extinct Hohenstaufen dynasty within their dominions.
In 1263 the duke quite luckless interfered in the War of the Thuringian Succession to support the claims raised by his mother-in-law Sophie of Brabant.
During the Imperial interregnum, he sided with the rising Bohemian king Ottokar II until his final defeat in the 1278 Battle on the Marchfeld.
[4] After Elizabeth's death in 1261, Albert married Adelheid (Alessia) (1242 – February 6, 1284/85),[5] daughter of Margrave Boniface II of Montferrat around 1263.