Dear Mr. Cox, Yes, I agree with David, these look like the famous Lipizzaner horses of the Vienna Riding School. In 1945 they were secretly moved out of Vienna and eventually reunited with the mares which had been moved to Czechoslovakia and rescued by Gen. Patton. You can learn all about it from the 1963 Disney flick on YouTube, “Miracle of the White Stallions.” Maybe this photo was taken at some point during the escape of the stallions from Vienna. Haha, but let’s not forget “Operation Cowboy,” that brought the Lipizzaner mares across the Czech border to Bad Kötzing in liberated Bavaria on the Regen River. These horses were partly herded, partly ridden, by American soldiers but also by a group of Cossacks who had defected from the advancing Soviet army. Maybe it’s them in the photo?!? TMI. Sorry. But you did ask!AJ
This used to be a regular event in Spain. There was a photo in James Michener’s book “Iberia” of a spectacular nude young man riding a white stallion into a river for a communal bath. I beat off to that photo for years.