Background
He was the fifth but third surviving son of Christian I, Duke of Saxe-Merseburg and Christiana of Schleswig-Holstein-Sonderburg-Glücksburg.
He was the fifth but third surviving son of Christian I, Duke of Saxe-Merseburg and Christiana of Schleswig-Holstein-Sonderburg-Glücksburg.
In order to give his three younger sons a proper land to live, Duke Christian I, before his death assigned to them in each case his own small territories as appanages. However, the allowances of them remained in the Saxe-Merseburg main line and with this, their powers over that lands were strongly limited. Philipp received in 1684 the town of Lauchstädt and founded the line of Saxe-Merseburg-Lauchstädt.
He was allowed to develop and rebuild the castle (which was strongly damaged during the Thirty Years" War) for himself and his family, and later used the castle church as a City parish church (German: Stadtpfarrkirche).
Philipp was completely devoted to his military career as an officer in the Imperial army against King Louis XIV of France and was killed in the Battle of Fleurus (1690). He died without surviving male issue, his second and only surviving son having died just one month before him, and predeceased his father.
Thereafter, Lauchstädt was merged back into the duchy of Saxe-Merseburg.
He was a member of the House of Wettin.