Before the Antietam Campaign:
He was a large man (perhaps 6' 4" tall) from an "old Prussian military family of the titled nobility", and was serving in the 2nd Brandenburg Regiment of Dragoons as the American Civil War began. He left his Regiment and arrived, through the Federal blockade, at Charleston, SC in May 1862. He joined J.E.B. Stuart as Captain, PACS in June.1

General Stuart was greatly impressed by von Borke, reporting:

"Capt. Heros von Borcke, a Prussian cavalry officer, who lately ran the blockade, assigned me by the honorable Secretary of War, joined in the charge of the First Squadron in gallant style, and subsequently, by his energy, skill, and activity, won the praise and admiration of all".2

von Borcke's 8 August 1862 appointment as Major was confirmed by the Confederate Congress on September 19th.3 Later in the month, Stuart again cited him in an after-action report:

"[near Brandy Station, Va, 20 Aug 1862] Maj. Heros von Borcke, my adjutant-general, was conspicuous in the charge, and led an important flank attack at the critical moment of the engagement…" 4

In the Antietam Campaign:
von Borcke was MGen Stuart's chief of staff (adjutant-general) on the Maryland Campaign.

The remainder of the War:
Major von Borke continued on Stuart's staff untill seriously wounded in action at Middleburg, Va [historical marker], 19 June 1863. He had recovered sufficiently to be present at JEB Stuart's death after the battle at Yellow Tavern, VA in May 1864. He was appointed Lieutenant Colonel, PACS as of 20 December 1864.5

After the War:
After the War he returned to Prussia, serving in the war with Austria (1866). He retired—for health reasons stemming from his 1863 wounds—to Neumarkt, East Prussia in 1867, then an inherited castle at Geisenbrugge. It was reportedly "his delight to fly the Confederate flag from its battlements".1

He published his memoirs of Confederate service (Zwei Jahre im Sattel und am Feinde. Erinnerungen aus dem Unabhangigkeitskriege der Konfoderirten, von Heros v.Borcke. Aus dem Englischen ubersetzt von Kaehler, Deutsche Original - Ausgabe. Berlin, E. S. Mittler und Sohn) in 1877. These were published in English in the US shortly after, and have been re-issued several times since. They are a popular resource, though perhaps not entirely reliable, containing significant exaggerations of von Borcke's role in the events of the War.

Heros Von Borcke