15thc perception on swallowtail merlons?

[Mark Knowles]

The period between the fourteenth century and the sixteenth seems to have been exceptionally violent in Northern Italy. Many castles were built or expanded over a few decades, only to be destroyed and rebuilt again in recurring cycles. A lot of the small towns and villages were surrounded by walls as well.

In the early 15th century, the period to which the vellum of the Voynich manuscript is dated, saw what are termed the 4 Wars in Lombardy. For most of the late 15th century there was peace with the Pact of Lodi.

The early 15th century saw major advances in the use of cryptography by the Italian States. I suspect that the extent of war and conflict over that period drove the advancement in cryptography.