Now, Deadline reports that another Game of Thrones prequel is in development at HBO, one that will be set 300 years before the War of the Five Kings, and will detail the beginning of the end for House Targaryen. Unfortunately, HBO declined to comment. Deadline also reports that the series will be created by George R.R. Martin and Ryan Condal (Colony) and will most likely be based on the Fire & Blood book that Martin released last November.

Below is the synopsis of Fire & Blood: This is one of the three Game of Thrones spin-offs that Martin himself confirmed on his blog back in May. The other is the aforementioned Naomi Watts series and the third one is currently still kept hush-hush. What really happened during the Dance of the Dragons? Why was it so deadly to visit Valyria after the Doom? What were Maegor the Cruel’s worst crimes? What was it like in Westeros when dragons ruled the skies? These are but a few of the questions answered in this essential chronicle, as related by a learned maester of the Citadel and featuring more than eighty all-new black-and-white illustrations by artist Doug Wheatley. Readers have glimpsed small parts of this narrative in such volumes as The World of Ice & Fire, but now, for the first time, the full tapestry of Targaryen history is revealed.

Game of Thrones  A House Targaryen Prequel is Currently in the Works - 80