During his time as Governor-General of Finland, he made large administrative reforms, introduced a postal system, improved and developed commerce and agriculture, and promoted education.

Per Brahe the younger, after completing his education by several years’ travel abroad, became in 1626 chamberlain to Gustavus Adolphus, whose lasting friendship he gained.

He reformed the whole administration, introduced a postal system, founded ten new towns, improved and developed commerce and agriculture, and very greatly promoted education.

"[citation needed] After the death of King Charles X in 1660, Brahe, as Lord High Steward, became one of the regents of Sweden[3] for the second time (he had held a similar office during the minority of Queen Christina, 1632–1644), and during the difficult year 1660 he had entire control of both foreign and domestic affairs.

[1] The Finnish town of Raahe (Swedish: Brahestad), which he founded in the year of 1649 in Ostrobothnia, is named after him,[4] as is the asteroid 1680 Per Brahe, discovered by Liisi Oterma at the Turku Observatory in 1942.