Harsha was the second son of Prabhakaravardhana, the first important king of
Pushyabhuti dynasty with its capital at Thanesvar. Pushyabhutis were the
feudatories of the Guptas, but had assumed independence after the Huna
invasions.
    Harsha was favoured to his elder brother, Rajyavardhana, by both his
father and the nobles. But Harsha expressed his reluctance to supersede his
brother. Rajyavardhana who became the ruler had to face problems from the
day of his succession to the throne. Grahavarman, the Maukhari ruler of
Kanauj and husband of Rajyasri (daughter of Prabhakara), was murdered by
Devagupta (the ruler of Malwa) who in alliance with Sasanka (ruler of Gauda
or Bengal) now occupied Kanauj and imprisoned Rajyasri. Rajyavardhana,
therefore, undertook a campaign against Devagupta and killed him but he
was deceived and killed by Sasanka. In the meanwhile Rajyasri escaped into
the forests of central India.
    Harsha now succeeded his brother at Thanesvar. His first act as the ruler
was naturally to rescue his sister and avenge the deaths of his brother and
brother-in-law, and was quite successful in both. He drove out Sasanka of
Gauda from Kanauj. Between 606 and 612 he brought most of northern India
(Punjab, Kanauj, parts of Gauda, Orissa and Mithila) under his control, and
assumed the title of ‘Siladitya’.
Harsha’s Military Conquests
Occupation of Kanauj In his first expedition, Harsha drove away Sasanka
from Kanauj who had occupied it after murdering Harsha’s brother. After
this, he not only unified Kanauj with Thanesvar but also made it his new
capital, which made him the most powerful king of north India.
Conquest of Valabhi His early relations with the rulers of Valabhi were
cordial because he was engaged in consolidating his position against the
Gupta-Gauda axis in the east. But soon Malwa became the bone of contention
between the two and so he had to turn his attention to western India. Nausasi
Copper Plate Inscription gives information about his expedition against
Valabhi. It resulted in the defeat of the Valabhi ruler, Dhruvasena II and his
acceptance of the position of a feudatory vassal.