Career
Blumenthal was lord of Steinhöfel (Brandenburg), Groß Möllen (Pomerania), Loiste and various other estates. He entered the Prussian Civil Service. In 1743 he was a "Councillor" of the War and Domains Directory, where he worked in Gumbinnen before being transferred to Königsberg in 1746.
In 1755 he became President of the War and Domains Chamber in Magdeburg, where he caught the eye of Friedrich the Great who in 1763 appointed him Privy State and War Counsellor and presiding Minister of the General War and Finance Directory as well as Vice President of the General Finance, War and Domains Directory in Berlin.
He was also responsible for the Provinces of Prussia and Lithuania, as well as the salt business. Frederick William World War II In December 1786 Mirabeau wrote "Blumenthal is a faithful accountant, an ignorant Minister.
Ambitious, when he recollects ambition, and to please his family. And full of respect for the Treasury, which he places far above the State.
And of indifference for the King, whom he more than neglected while he was Prince of Prussia."
Blumenthal first married on 2 October 1749 Katharina Sophie Auguste von der Groeben (1728–1750), daughter of the minister of state Wilhelm Ludwig von der Groeben (1690–1760).
They had the following children:
Elisabeth Luise Wilhelmine Amalie Henriette (1760–1826), married Freiherr Ernst-Georg von Steinberg-Bodenberg (died 1797)
Friederike Amalie Albertine (born 1765) married Friedrich Heinrich von Podewils (1746–1804)
Ferdinand Friedrich Heinrich Christian (1765–1778)
Charlotte Auguste Johanna Luise (1766–1835) married Valentin von Massow (1752–1817), High Marshal of Prussia und Intendant of the royal palaces. His father (also called Valentin) was a fellow-minister of Joachim von Blumenthal, elevated to the countship in the same year.