Who was Harṣhavardhana and when did he become king?

Harṣhavardhana became king in 606 CE at Kannauj. He belonged to the Puṣhyabhūti dynasty. The earlier capital was Sthāneśhvara. He expanded his empire over large parts of northern and eastern India. He was called 'Mahārājādhirāja', meaning 'Great King of Kings'.