Your idea for a prequel series (backstory spoilers)

Since we keep speculating about it, why not have a thread for it?

If you were part of a HBO brainstorming group coming up with ideas for a prequel series set in Westeros, what era (or eras) would you pick? Who would be your main protagonists? Antagonists? What climax would your series build towards?

Rob's Rebllion? The Dance of Dragons? Age of Heroes? The Conquest?

Here's mine:

Fire and Blood. A series largely mixing the events of the Blackfyre Rebellions and the Dunk and Egg series, with the central plot point seemingly being the Blackfyre Rebellions, but as those Rebellions begin to diminish, the focus shifts towards the main characters becoming aware of destiny... And dragons.

The odd thing about this story, is that the Starks wouldn't really be the main characters. Martin clearly has plans for Starks during this time frame, but with the possible exception of the "She-Wolves of Winterfell" he teased, the House that acts as main protagonists to Game of Thrones seems restrained to the North. Instead, our main protagonists would primarily be Southern born Targayens and their hangers on. Dunk and Egg would grow into the main protagonists, while our starter hero would probably be Lord Bloodraven, perhaps with him becoming more ambiguous and fading a bit into the background as his powers grow.

So, here's how I'd plan it: Season One opens with a tournament under King Aegon the Unworthy, a place to give some exposition for all Seven Great Houses and our Great Bastards. You'd have young Daeron and his Dornish Fiancé, the Tyrells being angry at their enemies present, the Greyjoys with a sharp eyed boy named Dagon, the Baratheons acting like the bestest buds with the Targaryens, and maybe for some irony, Lord Lannister sharing a drink with his old acquaintance, ancient and nearly blind Lord Cregan "Old Wolf" Stark. Aegon the Unworthy acts disgusting towards his sister wife, Aemon the Dragonknight clearly trying to enforce some behavior on his brother, and finally focus on a trio of high born bastard boys, where Daemon Water maybe pulls Aegor Rivers off Brynden Rivers. The first episode would establish everything we need to know, maybe feature Cregan reminiscing darkly about the Dance of Dragons, and end with Aegon the Unworthy getting into an argument with Daeron before suddenly acknowledging his bastards and giving Daemon the sword Blackfyre.

Season One would then cover the first Blackfyre Rebellion, showing Bloodraven becoming aware of his abilities and being accepted by Daeron as a true brother (you could get some nice feels out of Daeron giving the albino bastard Dark Sister.) Season Two would start Dunk and Egg as Bloodraven starts really exploiting his powers and unnerving even his allies while perhaps showing Aegor forming the Golden Company and winning some major battles, Season Three would continue Dunk and Egg and feature the Second Balckfyre Rebellion and the start of the Third, Season 4 would showcase the Third, the She-Wolves of Winterfell, and Aegon V coming to the thrown, while Bloodraven becomes the Three Eyed Raven in the North. Season Five would feature Aegon V winning the Fourth Rebellion, Baratheon's Rebellion, and the Tragedy at Summerhall, while Bloodraven ventures all the way North and retires to his tree.

Your idea for a prequel series (backstory spoilers)