Complex sentence: Louis extended the duchy of Bavaria and founded many cities, like Landshut in 1204, Straubing in 1218 and Landau an der Isar in 1224.
Split into simpler sentences: Louis extended the duchy of Bavaria and founded many cities. Among the cities he founded were Landshut in 1204, Straubing in 1218 and Landau an der Isar in 1224.