Historically significant events in Europe between 1404 and 1438

[Mark Knowles]

Important to whom? 
Yes there are major, famous events, the best known have been listed above.
But that does not necessarily mean that other, lesser known events may have been more relevant, pressing, or consequential to the specific group that made the Voynich manuscript. How could we know what was important to them when we don't know who they are?
Another thing we don't know is whether the Voynich might be a version of older material. For all we know, it may be an adaptation of something originally created say in the 13th century or some other time. 
So while the C14 provides an end date for such a timeline, the start date is uncertain.

I anticipated the "Important to who question". If you were a medieval peasant then the events of your own life would be more important than major political events. So of course important is a subjective word. However if I were to buy a book called "European History from 1404 to 1438" it would not focus on the life of one ordinary peasant.

In this question, I have nowhere stated that the knowing the main events of European History from 1404 to 1438 will answer all the questions relating to the Voynich. However I would doubt that anyone can say with confidence that they are irrelevant.