In the last section, I ask the question: who can be symbolized by the skull on the facade of the university in Salamanca. As noted in the comments, the question is very confusing and "whoever stands" is unclear.
Therefore, I decided to take the trouble and draw a family relationship diagram. So will it be clearer? From the Catholic Kings, I hold four arrows - one for their daughter, Queen Juan I, the other three to the skull. From them is a sign for Juan I - sister. So who can hide below?
At the time of construction, of the five children of the Catholic Kings, not counting the dead and the dead in early childhood, only two were left. The skull is a descendant of the kingdom, which does not live until 1533.
The closest to the queen, the famous skull of the frog: Juan Aragon (1478 - 1497) - the only heir to the male throne of Aragon and Castile.
The next inheritance rights are: Isabella of Aragon (1470 - 1498) - Empress of Portugal, heir of the Castilian Kingdom.
And the last skull: Mary of Aragon (1482 - 1517) - queen of queen of Portugal.
I can not say for sure whose idea it is. Perhaps it is in the context of the official mention of the possible heirs and the annexation of Portugal. Esli we accept the theory already mentioned Alicia M. Canto, and this construction is funded by my Juana, then it could be a manifestation of feminine sentimentalitas: all the same brother and brother, with whom he spent his childhood and his teen. And, given the emotionality of their family, it is possible that he is deeply attached to them and loves them so much.
Even the presence of frogs on the skull of the Crown Prince is easier for me to understand if the construction is led by a woman. All the same thing is believed that female sex is a pure masculine, so that sister can signal a warning to others, from where his brother died.
In the first part I have quoted local legends, from which follows that in the 15th-15th centuries the frog symbolized lust, lust, death and punishment for this sin. But we will not rely on local tales, here are some works by experts at that time.
The girl and the death. A teenage girl, you can say almost naked, crying in regret, and kneeling skeleton gives her a cross, urging her to think again before it's too late. On the bone you can consider some lyagv, the biggest dangles under the skull. I think the clue is clear to everyone, because what sin threatens the death of the young naked. Who does not believe that the class of love can cause a sad ending, there is a book by Benjamin Garcia Hermandes. In it he claims that the frog is merely a visualization of the Spanish proverb "When the frogs grow hair", the analogue of our "When the cancer is at the whistle of the mountain." This architect dock implies that the resurrection is not possible, but in such an encrypted way that the Inquisition does not guess. I just do not understand to whom this message is addressed? If the Inquisition can not solve the puzzle, then the rest will become more difficult. So I remain true to "love theory" and ready to tell you how it happened. Next time
On this one can stop, but do not carry fragments of Jerome Bosch's own painting "Seven deadly sins and the last four things" I can not. Currently, the top of this table is on display at the Prado Museum. Scientists have not been able to establish the year of its creation, but the Boschas died in 1517, so it fits perfectly.
This is the secret of the kingdom. The only son of the Catholic kings, the young heir died of his excessive zeal for joy lovers. Many people think that this can not, and this is all ecclesiastical horror stories, but unfortunately, sometimes love kills in this way. By the way, the story is very interesting, but for him needs to write a separate post, where at the same time one can mention the odd father role of the prince in many deaths in the royal family.