He studied at Lund University, where he graduated in law, after which he was employed in the Judicial Commission and the Auditor General Division.

In 1794 Rosenblad was appointed Secretary of State in the Civil Division, and gained increasing influence in the Chancellery.

He was a close associate of Gustav IV Adolf, but when the latter was deposed Rosenblad does not seem to have come to his defence.

Liberals, however, considered Rosenblad the embodiment of the blindly obedient yes-men among the royalists.

On 31 August 1829 Rosenblad was appointed Minister of Justice, and remained in that position until 6 February 1840.