Analysis of information sources in references of the Wikipedia article "Ferdinand von Zeppelin" in English language version.
In November, 1908, the Crown Prince steered the largest Zeppelin then made [...]
In 1887 Zeppelin submitted a memorandum to the King of Württemberg in which he explained in detail the requirements of a really successful airship and stated many reasons why such airships ought to be large and of rigid construction. However, nothing of importance was actually accomplished until he resigned as a General in 1891 in order to give his full time to his invention.