Complex sentence: After his death in 606 CE, his eldest son, Rajya Vardhana, ascended the throne, however he was soon murdered by a rival, which led to Harsha also known as Harsha Vardhana, ascending to the throne at age 16.
Split into simpler sentences: After his death in 606 CE, his eldest son, Rajyavardhana, ascended the throne. Not long after, Rajyavardhana was murdered by a rival, which led to Harsha ascending to the throne at age 16.