Complex sentence: In the north and west, the collapse of Harsha Vardana's kingdom (606--647 CE) gave rise to many smaller kingdoms, leading to the rise of the martial Rajputs clans across the Gangetic plains.
Split into simpler sentences: In the north and west the collapse of Harshavardana's kingdom (r.606--647 CE) gave rise to many smaller kingdoms. This led to the rise of the martial Rajputs clans across the gangetic plains.