Philip III was the second son of Christopher II and Princess Cecilia of Sweden.

He inherited Baden-Rodemachern after the death of his brother Edward Fortunatus in 1600, and took up residence at Ettlingen Castle.

In 1605, Philip enlisted soldiers to liberate Baden-Baden, which had been occupied by Baden-Durlach since 1594.

The attempt failed, and Philip's cousin George Frederick took him prisoner.

Philip was held in Durlach, and later at Hochburg Castle, where he died childless in 1620.