He was the descendant of Ksemankara Deva who is believed to be the founder of the Bhaumakara rule in ancient Odra and also the earliest organizer of the Varna system in the region.
Sivakara Deva I pursued a career of conquest in the eastern part of India establishing the Bhaumakaras as the supreme power in the whole region during his lifetime.
Historian R.C.Banarjee identifies the mention of Rarh in the Bhaumakara inscription with the territory that comprised around the modern Bankura district confined between the rivers Ajay and Rup Narayan.
The Dhenkanal charter of Tribhuvana Mahadevi I provides a poetic indication of a fierce battle between the armies Kalinga comprising large number of war elephants and that of Utkala's Bhaumakara dynasty which ended in the later's victory.
[11] Sivakara Deva I is also recorded to have sent an eminent Mahayana Buddhist scholar named as Prajna with the manuscript called Gandavyuha Sutra to the Tang court of emperor Dezong in China personally autographed by him.
The Angul inscription of his descendant Dharma Mahadevi praises him as "Unmattasimha acquired the ever-lasting renown and resembled the moon covering all regions with great lustre and delighting people by dispelling the heat."