Airmail by Zeppelin

In a shoebox, among a number of postcards at a flea market, I found a card that immediately caught my attention. The card featured an aerial photograph of an enormous 91-meter-high monument. It turned out to be the Völkerschlacht-Denkmal in Leipzig. It commemorated the massive slaughter perpetrated by Napoleon's army in October 1813. The monument is located southeast of the city of Leipzig and was inaugurated in 1913 by German Emperor Wilhelm II. The photo was taken from a Zeppelin airship. After turning the card over, it turned out that it had been sent from the airship on June 13, 1914, as evidenced by the stamp. The card was addressed to someone in Amsterdam. However, because the card was insufficiently franked (5 Pfennig stamps had been affixed, whereas it should have been 10 Pfennig), a blue letter T was applied to the card. A postage due stamp is missing because the card was placed in a postage-paid envelope (with a window) in Amsterdam, meaning only the address was visible and the message could not be read. Furthermore, a fine impression of the Zeppelin Sachsen's onboard stamp was applied, also bearing the date June 13, 1914. Something about the Zeppelin itself. The Zeppelin was named Sachsen and was registered as LZ 17. It was owned by DELAG, the Deutsche Luftschiffahrt Aktien Gesellschaft, the airline founded by Count von Zeppelin in 1909, the first in the world. The airship made its maiden voyage on May 3, 1913. The Zeppelin was 142 meters long and had a diameter of nearly 15 meters. During 419 flights, 9.837 passengers were transported, until the airship was requisitioned by the German army due to the outbreak of the First World War. In 1916, the Zeppelin was decommissioned. A huge chunk of history on such a small card! Sent on June 13, 1914, and two weeks later, on June 28, 1914, the assassination of Austrian Crown Prince Franz Ferdinand and his wife in Sarajevo. The trigger for the outbreak of the First World War. And a card like that in a shoebox at the flea market. Have you ever found something with such a history?