The von Blumenthal family are Lutheran and Roman Catholic German nobility, originally from Brandenburg-Prussia. Other, unrelated, families of this name exist in Switzerland and formerly in Russia, and many unrelated families (some of them Jewish) called "Blumenthal", without "von", are to be found worldwide. The family was already noble from earliest times ("Uradel"), dating from the days of the Holy Roman Empire in the Middle Ages, long before the creation of the Kingdom of Prussia and the German Empire, and different branches acquired different titles over time. All living members of the noble family are descended from Heinrich (V) von Blumenthal (1654–93), whose baronial status was limited to the borders of Brandenburg. Other members of the family were raised to allodial baronies (Freiherren), all of which are now extinct, or to countships, of which only one line survives.
Like the von Grabow family, whose descendants have included Pushkin, the Blumenthals were originally a branch of the Ammendorf (or Amendorf ) family, who inherited the estates of Blumenthal and Grabow from the only daughter and heiress of Nikolaus von Blumenthal, first referred to in a document of 1240. His family probably originally came from Bloemendaal in Holland and re-located first to Blumenthal near Verden in the diocese of Bremen and thence to Blumenthal in the Archdiocese of Magdeburg, where they were vassals of the Wendish Counts of Plotho,naming each settlement after the previous one.
The Plotho family expanded its estates in the Prignitz in the 13th century, bringing Nikolaus von Blumenthal with them. There he named the villages of Blumenthal and Grabow after his properties in the Archdiocese of Magdeburg. The family of his son-in-law, Ruthger von Amendorf, had also come from the country around Bremen. They inherited Nikolaus von Blumenthal's estates and took his name. The castle of Horst, near Blumenthal in the Prignitz, was the family seat for over 600 years, until 1810. The family also claimed a legendary descent from the Roman Emperor Florianus, as well as from the Arthurian knights Garel and Daniel von Blumenthal, whose stories are told in 13th-century poems by Der Pleier and Der Stricker, respectively.