He was born on 23 July 1835 inside the fortress of Ehrenbreitstein on the Rhine, into the von Borckes, an old Pomeranian noble family. His father Theodor owned the manor at Giesenbrugge in the New March and sat in the Prussian House of Lords from 1856; his mother Therese died in 1847, when he was a boy. He was schooled at the Franckesche Stiftungen in Halle, commissioned into the Prussian cavalry in 1855, served with the Guards Cuirassiers, and returned from a spell of study to active duty with the 2nd Brandenburg Dragoons. Then the money ran out. Debt forced a second lieutenant with an aristocratic name and no income to resign, and in 1862 he sailed for the Confederate States - a government that had seceded to preserve slavery, and one short enough of trained cavalry officers not to ask hard questions of anyone offering to serve. He ran the Union blockade carrying a straight sword of Solingen steel so large that it became famous on its own account.

By the end of the month he had reached Richmond, and on 1 June 1862 the Secretary of War, George W. Randolph, commissioned him captain and posted him to Major General J.E.B. Stuart. He was enormous - tall, heavy, and swinging that Solingen blade - and the Confederate cavalry named him the giant in gray almost immediately. Reporting on the celebrated ride around McClellan's army, Stuart wrote that von Borcke, a Prussian officer who had lately run the blockade, joined in the charge of the First Squadron in gallant style and by his energy, skill and activity won the praise and admiration of all. Promotion to major came that August, and he rode as Stuart's adjutant general through the Northern Virginia and Maryland campaigns. When the young artillerist John Pelham was killed at Kelly's Ford, it was von Borcke that Stuart detailed to escort the body home to Richmond. Three months later came Middleburg and the neck wound that took him out of the war for the rest of the year.

He recovered enough to resume staff work in the spring of 1864 and was at Yellow Tavern in May when Stuart was shot and killed. In December he was made lieutenant colonel and voted the official thanks of the Confederate Congress, then sent by Jefferson Davis on a diplomatic errand to Great Britain - a mission for a cause with weeks left to run. What came out of it all was a book. Memoirs of the Confederate War for Independence appeared in 1866 from William Blackwood and Sons of Edinburgh, and it is the reason anyone outside Pomerania still knows his name. Written by an outsider with access to Stuart's headquarters and a European's eye for what Americans took for granted, it remains one of the most quoted foreign accounts of the war - and, like most memoirs from that side, a document of loyalty to comrades that says little about what those comrades were fighting to keep.

Prussia took him back. He fought in the Austro-Prussian War of 1866 on the staff of Prince Friedrich Karl and was decorated with the Order of the Red Eagle, then retired in 1867 with his wounds still troubling him. He bought an estate at Sichts, now Zychce, and after his father's death moved back to Giesenbrugge to run the family land. He married Madalene Honig at Gralow in 1867; they had three sons. When she died in 1883 he married her younger sister Tony, and their daughter, born at Giesenbrugge in 1885, was christened Caroline Virginia Magdalene - Virginia for the state where he had spent two years of his life. He is said to have raised the Confederate flag over the estate as a matter of routine. In 1884 he crossed the Atlantic again to see old comrades: Wade Hampton, William H. F. Lee, Matthew C. Butler. Then he went home and stayed there.

He died in Berlin on 10 May 1895, of sepsis traced to the projectile still sitting in him from Middleburg, and was laid in a mausoleum in the old cemetery at Giesenbrugge. Half a century later the war reached him anyway. Red Army troops destroyed the headstone during the Second World War, and afterwards the border moved west: the New March became Polish, the village became Gizyn, and the German families who had farmed there for generations were gone. The grave stayed. In 2008 the Sons of Confederate Veterans installed a replacement stone in a Polish village cemetery - the last odd turn in a life made almost entirely of odd turns. Gizyn is a scatter of houses among fields and small lakes east of Mysliborz, and the visitors who come looking for the grave are usually American.