Complex sentence: He published more than fifty juvenile books, many under the pen name Christopher Webb, including the seven-volume "Treegate" series of historical fiction, which takes place during the American Revolutionary War and the War of 1812.
Split into simpler sentences: He published more than fifty juvenile books, many under the pen name Christopher Webb. These include the seven-volume "Treegate" series of historical fiction, which takes place during the American Revolutionary War and the War of 1812.