[1] The date of his birth is unknown, but Eugen Alexander Franz was baptised on 11 January 1652 in Brussels.

[1] After the death of his father, Eugen Alexander Franz succeeded to the positions of Postmaster General of the Imperial Reichspost and the Spanish Netherlands.

In 1681, the last Habsburg King of Spain Charles II appointed Eugen Alexander Franz from a count to a prince, and Leopold I, Holy Roman Emperor made him an Imperial prince in 1695.

[2] In 1702, he moved his postal system's headquarters from Brussels to Frankfurt am Main where it originated.

Eugen Alexander Franz and Anna Adelheid had the following children: After the death of his first wife, Eugen Alexander Franz married Countess Anna Augusta of Hohenlohe-Waldenburg-Schillingsfürst, daughter of Ludwig Gustav, Count of Hohenlohe-Waldenburg-Schillingsfürst and his second wife Anna Barbara von Schönborn.