BAVARIA, LOWER When Bavaria was partitioned in 1255 Henry I, the younger brother, took LOWER BAVARIA (NIEDERBAYERN).
These were the southern lands of eastern Bavaria: the Danube valley from below Regensburg to above Passau, the Isar valley from below the Bishopric of Freising, the valley of the Inn from its confluence with the Salzach, and the region of the Bayerischerwald between the Danube and the Böhmerwald.
Henry left three sons when he died in 1290, and between them they left three sons. Henry had been a quarrelsome man, and Lower Bavaria saw much fraternal fractiousness among his successors. Eventually in 1333 the disputes over territory were stilled as only one of Henry’s grandsons survived. When he died in 1339 he left a young son, who died the following year. The Emperor Louis IV had taken out the insurance policy of betrothing one of his daughters to this youth, and was his heir in 1340.
In 1349 and 1351 Louis’s six sons partitioned their inheritance. Stephen II, the younger son of his first marriage, took part of Lower Bavaria with capital at Landshut, while two of the sons of his second marriage took a smaller share with capital at Straubing. The Straubing line died out in 1425 and its lands were shared out among the remaining Dukes in Upper and Lower Bavaria. The Duke of Bavaria-Landshut became the richest and most powerful of the Dukes, acquiring a considerable share of Upper Bavaria in 1445. The last Landshut Duke died in 1503 and, after some fighting, Bavaria was reunited under the Duke of Bavaria-Munich. He introduced primogeniture to prevent any further partition but his wife and second son between them forced a new partition on his heir. Louis X became Duke of a revived Bavaria-Landshut but he did not marry and with his death in 1545 the Duchy was finally reunited.
In present-day Bavaria NIEDERBAYERN is an administrative region crossed by the Danube, the lower Isar and with the lower Inn as its boundary with Austria. It is very similar to the old Lower Bavaria, but it includes Passau, a Prince-Bishopric in the later middle ages, and it has lost the lands east of the Inn that were then part of the Bavarian Duchy.