Frederick Louis was the Duke of Landsberg from 1645 until 1681, and the Count Palatine of Zweibrcken from 1661 until 1681.
Frederick Louis was born in Heidelberg in 1619 as the only surviving son of Frederick Casimir, Count Palatine of ZweibrckenLandsberg. After his fathers death in 1645, Frederick Louis inherited his territories devastated by the Thirty Years War. To a limited extent he contributed to the reconstruction efforts and he promoted trade to stabilise the situation. In 1661 he inherited the Duchy of Zweibrcken, another territory devastated by the war, following the death of Frederick, Count Palatine of Zweibrcken. He died at Landsberg Castle, near Obermoschel, in 1681. With the sons of his first marriage predeceased and the sons of his second morganatic marriage illegitimate, he was succeeded by King Charles XI of Sweden.
Source: Wikipedia