Sigmund Friedl (1851, Lipník nad Bečvou, Moravia – 1914, Vienna) was one of the most famous Austrian philatelists.
He had great success with his shop, for example, he sold the unique Tre Skilling Banco for a sum of 4,000 florins to the famous collector, Philipp von Ferrary.
Through his good relationship with the post, he was able to cheaply obtain the remaining stocks of several postage stamps and resell them.
Finally, Sigmund Friedl established his own stamp museum in his villa in Unterdöbling.
The forged stamps were mainly forgeries of the Mercury series issued in 1851, which were sold to collectors with fraudulent intent.