OK, let's start from one of my favourite artist: Jeroen Anthoniszoon van Aken, probably best known by the name of Hieronymus Bosch (this was actually the name of his town, Den Bosch).
Unfortunately we don't have much information about his life, which seems to have been very plain and ordinary (born, married, died)… But his works speak for themselves. They are so rich and dense in meaning that I could spend hours looking at them.
I deliberately leave all the strictly religious motifs aside. Until the Reinassance, when man put himself -finally- at the centre of the universe, art could not exist without religion, although artists managed to sneak away sometimes, as Bosch did.
Although it may not be immediately apparent, as for other painters, I find Bosch very sexual. His depicition of bliss in The Garden of Earthly Delights is very explicit, and many other works bear the traces of a direct relationship with lust and sex.
Some critics believe that he belonged to the sect of HominesIntelligentiae, preaching free love and nudity (at the beginning of 1400! Quite ahead of Woodstock!).
Here are some details from the The Garden of Earthly Delights.
The symbols are all there, fruit (cherries and strawberries were considered symbols of passion), birds (robin was another icon of lust, I really can't explain why). Another recurring motif is the color red. See also the The Seven Deadly Sins and the Four Last Things, where a woman's sex is hidden by a frog (in the punishment section, of course). Bosch's works, this one in particular, are very physical, the body is a powerful instrument to express feelings and narrate stories, without that all-catholic sense of prudery that emerges now and then in art history (see the Braghettone...). What contemporary Italian Christian would describe the Garden of Delights like that? We would probably put much different things there...