"Summer's Triumph" is a tapestry created in Bruges, Belgium in 1538 - Bayerisches National Museum. Several classic-shaped UFO-like objects are clearly depicted in the sky near the top. It is thought that the inclusion of these might have been politically motivated in effort to sway local opinion by associating UFOs with the current rulers in order to claim divine intervention in their political careers.
This is another 15th century tapestry which depicts scenes from the life of Mary. UFO-shaped objects can also be clearly seen it this one. This is also on display at the French Basillica Notre-Dame in Beaune, Burgandy.
This illustration, from the French book "Le Livre Des Bonnes Moeurs" by Jacques Legrand, housed in Chantilly Condé's Museum (ref 1338 ,297 part 15 B 8), has created much controversy. Some have said this is a balloon but balloons did not yet exist in France in 1338. This is difficult to therefore explain away, especially since many modern UFO sightings have been documented as being a sphere-like object.