 Being in direct line of succession to the throne of Oldenburg, as their uncle the hereditary Grand Duke Augustus was unmarried at the time, both boys were given the same extensive education by their grandfather Duke Peter as he had given his own sons and were regularly sent on instructive trips around Germany to broaden their education.In May 1829 his grandfather died and after the death of his brother Alexander in November of the same year, Peter's maternal uncle, Tsar Nicholas I of Russia sent for Peter, and named him a colonel in the Lifeguards.He quickly rose through the ranks and was subsequently appointed lieutenant general.