Complex sentence: Joseph Clemens, Elector of Cologne and Archbishop-Elector of Liège, and, more significantly, his brother, Max Emanuel, Elector of Bavaria who, after the Spanish throne had been lost with the death of his son, Joseph, now sought compensation elsewhere.
Split into simpler sentences: Joseph Clemens, Elector of Cologne and Archbishop-Elector of Liège, and, more significantly, his brother, Max Emanuel, Elector of Bavaria. After the Spanish throne had been lost with the death of his son, Joseph, the Elector now sought compensation elsewhere.