The Rains Of CastomereThe Rains of Castamere come from Game of Thrones S3E9.There was a man called Roger Reyne who was Lord of Castamere and Tytos Lannister’s bannerman, but he was too proud and deemed his liege Lord Tytos as a tender,weak man and tried to revolt.
Therefore, Tywin Lannister who was Tytos' eldest son and heir, marched to destroy his house. He put the torch to their castle and executed all the members of house Reyne, by then red lions all perished.
The bard in the story made this song to praise Tywin Lannister for his deed and it was well known to all lands.
The sentence “In a coat of gold or a coat of red” from lyrics is because of their house arms. House Reyne’s arms is a red lion and Lannister’s a gold one. And “rains” means Reyne, it’s a play on words. The rains weep over his hall and not a soul to hear, because they weeped and all died.
