You can quickly assemble a House of the Dragon Cosplay costume at Celtic WebMerchant. Here you will find a wide range of medieval clothing that you can use to cosplay your favorite character from House of the Dragon. House of the Dragon is the first Game of Thrones prequel series from HBO, based on the book Fire & Blood, by George R.R. Martin. This series tells the fate of the ruling Targaryen family in the lead-up to a devastating succession war, known as the Dance of the Dragons. The story takes place over 200 years before Game of Thrones and shows why House Targaryen was no longer as powerful around the birth of Daenerys.