The mission was successful, and Doenhoff also received noble title of Fürst from the Holy Roman Emperor.
He became titular Governor of Dorpat (1627–1634) (although already in 1625 the town had capitulated to Sweden and was never reobtained by the Poles); from 1633, Count of the Holy Roman Empire (along with Ernst and Gerhard von Dönhoff); Governor of Sieradz (1634–45); Court Marshal of the Queen (from 1639); and starosta of Wieluń, Lauenburg (Lębork), Radomsko, Bolesławiec, Sokal, Małoszyce, Sobowidze and Klonowo.
Doenhoff was influential and wealthy, enabling him to fund several interesting construction projects, mostly in Sieradz Province.
He ordered the rebuilding of a medieval castle at Bolesławiec (of which he was starosta), on the Prosna River, into a new residence, complete with Italian garden.
Toward the end of his life, he ordered the construction of a family necropolis, centered around a domed chapel, in the Jasna Góra sanctuary at Częstochowa.