He was the fourth of eight children of the Protestant pastor Georg Stephan Alexander Seidel and his wife Anna Margarete (née Faust).
He established close contacts with the modern North German book trade and created a wide network of relationships in art and culture, church and politics, state administration, education and science.
[citation needed] Contemporaries (such as the publisher Friedrich Christoph Perthes in 1823) praised Seidel's extraordinary business acumen, which was always coupled with a comprehensive sense of social responsibility.
Like the Prussian Reform Movement in Prussia, Maximilian von Montgelas, supported by the Barons of Aretin, Seidel pushed for administrative modernisation in Bavaria.
Conversely, Seidel supported Montgelas' reforms by publishing a journal entitled The Genius of Bavaria under Maximilian IV from 1801 to 1804, edited by Johann Georg von Aretin [de].
Here, from 1810 onwards, a common Bible edition for Catholics, Lutherans and Reformed was published for the first time with royal Bavarian privilege.
On the Schlossberg he had elaborate terraced gardens laid out and a "Pantheon" with 18 portrait busts of important scholars, churchmen and statesmen erected.
Among other things, he created a life-size Minerva statue made of lead for Sulzbach, which is considered a prime example of the newer Bavarian metal casting and today adorns the backyard in front of the Seidel Hall.
The discovery of the picture story "Der Kuchenteig" by Wilhelm Busch was considered a "sensational find",[6] which represents a previously unknown preliminary study for Max und Moritz.