First off all I want to thank you for the one of the best fantasy novels I ever read. Then I would like to ask one question: In the SOS Jora Mormont told to Dany that Aegon The Dragon had two wives and she could take two husbands. The question is if there were any other precedents of polygamy among Targaryens besides Aegon the First.
Yes, there were.
Maegor the Cruel had eight or nine wives, I seem to recall, though not all of them were simultaneous. He beheaded a few of them who failed to give him heirs, a test that all of them ultimately failed.
There might have been a few later instances as well. I'd need to look that up... (or make that up, as the case might be).