He passed studentexamen in Uppsala in 1941[1] and like many others during the World War II, Rudberg made his way to the military.

[3] During these years, Rudberg was assigned to artillery weapons service and it resulted in service on torpedo boats, destroyers and cruisers and the training ship Prins Carl, where he for some years led the navy's radar and fire-control system school.

[3] Another important appointment was as aide-de-camp to the then Chief of the Navy, Admiral Stig H:son Ericson.

[3] Rudberg was commanding officer of the First Destroyer Flotilla from 1967 to 1970 and promoted to senior captain the same year.

[2] Rudberg was section chief in the Defence Staff from 1970 to 1973 and was promoted to rear admiral the same year.

[5] At this time, the security policy environment had deteriorated in Sweden's region through the Poland crisis and the increase in tension between the superpowers.

Rudberg managed, however, personally to force comprehensive safeguards regarding timing and quality for a production in Sweden.

Likewise, he showed a great commitment to improve the protection against the ongoing violations of foreign submarines in Swedish waters.

[2] Rudberg was convinced that the navy should be accorded greater importance in the Swedish defense, and he argued for this in the military management.

Meanwhile, Sweden was subjected to repeated underwater violations and Rudberg was forced to redirect the emergency preparedness system to meet the threats.

[7] In a news article in Svenska Dagbladet in 1998, Rudberg explained that after Prime Minister Olof Palme's assassination in Stockholm on 28 February 1986, Rudberg, who until recently had been the Chief of the Navy, had called the Supreme Commander Lennart Ljung and announced that he was ready to travel to Washington, D.C., where Sweden's naval chief had his place in the event of a war.