Historical 3x5 postcard signed on the front by Archduke Joseph Ferdinand of Austria in fountain pen ink.  Postmarked in 1915.  Some light creasing and toning, otherwise, excellent. Comes with an unsigned photograph.
 
(1872-1942) Archduke Joseph Ferdinand of Austria was an Austro-Hungarian Archduke, military commander, from 1916 Generaloberst, and an early advocate of air power. He later retired to life as a common citizen of Austria, and was briefly imprisoned in Dachau during the Nazi era. In August 1914, he took the command of the XIV Corps, succeeding General der Kavallerie Viktor Dankl von Krasnik, who had taken command of the First Army. His Corps was part of the Third Army of General Brudermann. In early September 1914, the devastating battles at the Zlota and Gnila Lipas practically destroyed the Third Army, and the Fourth Army under General Auffenberg was also decimated following Rawa Russka. The Archduke was chosen to replace Auffenberg on October 1. Meanwhile, the XIV Corps was taken over by Feldmarschalleutnant Josef Roth on 30 September.
 
Joseph Ferdinand was to remain in command of the Fourth Army until early June 1916. At this time, General Aleksei Brusilov launched the Brusilov Offensive at the juncture of the Fourth and First Armies. The result was that Joseph Ferdinand's trenches were obliterated by the Russian bombardment, and his troops surrendered en masse to the advancing Russians. In light of this massive setback, the German High Command insisted on his removal from command. The Archduke went into retirement and was replaced by General Tersztyanszky.
 
Following the accession of Kaiser Karl in November 1916, Archduke Joseph Ferdinand was offered the post of Inspector General of the Imperial Air Force. The Archduke brought his interest in ballooning to the post, although the Army HQ immediately objected to the appointment. In spite of their reservations, the Archduke was appointed on 8 July 1917 and he remained there until 3 September 1918.
 
Theodore von Kármán, then an Oberleutnant in the Austro-Hungarian Luftarsenal, found Joseph Ferdinand to be an "ignorant and pompous fellow." As Inspector General Joseph Ferdinand visited the Austro-Daimler Company where he was shown the company's first six-cylinder airplane engine by Ferdinand Porsche. In his autobiography, von Kármán relates an exchange between Joseph Ferdinand and Porsche:
 
"Is this a four-cylinder engine?" the Archduke asked.
"Yes, Imperial Highness."
"Well, then, why are there six cylinders?" he demanded.
Porsch,e with a side wink at m,e replied: "The last two cylinders are reserves."

Comes with a full Letter of Authenticity from Todd Mueller Authentics.