House of the Dragon zooms the map of Westeros directly into the Riverlands

The war has officially arrived in House of the Dragon Season 2. And similar to the second season of game of Thronesthis means that the geography of Westeros will play a much larger role in the series and in our understanding of it. In fact, the Green Party’s war council in the third episode of this season is probably just a preview of the important tactical discussions to come.

The show has never been shy about giving away a lot of details and letting viewers piece things together for themselves, but with war looming, it’s especially important to keep a close eye on what people are arguing about. To prepare you for the Targaryen civil war, here’s a quick breakdown of what everyone was talking about in Episode 3 and why the fight for the Riverlands is so damn important to both sides.

[Ed. note: This story contains spoilers for House of the Dragon season 2, up to episode 3.]

The first key to understanding the significance of the Riverlands in Dance of Dragons is understanding their geographical place in the story. Here’s a map if you want to brush up on your knowledge:

Graphic: Austen Goslin | Image source: tear above A Wiki of Ice and Fire

As we can see, in contrast to the battles in Season 2 between the Lannisters in King’s Landing and the Starks in Winterfell in game of Thronesthere is not much distance between House of the Dragon‘s two Targaryen factions. In fact, the only thing separating them is Blackwater Bay on one side and the Riverlands on the other. And the Riverlands practically surround the small islands of Dragonstone and Driftmark, where Rhaenyra and her allies currently live.

Another important aspect of understanding the Riverlands is understanding the Tullys. House Tully are the lords of Riverrun and have traditionally been the stabilizing force in the region. However, as Jason Lannister points out in the small council meeting at King’s Landing, the Tullys are currently led by Grover Tully, an old man unable to hold his own house together, let alone the rest of the Riverlands, which is heading toward open war. This means that the region is almost entirely up for grabs and in very open conflict – as we see at the beginning of the episode with the Blackwoods and the Brackens.

It is precisely this power vacuum that leads Ser Criston Cole, the newly promoted Hand of the King, to conclude that he should forcibly head into the Riverlands with a small team to subjugate the various castles and their lords to the crown. To complete his plan, Criston says he will take Harrenhal and bring the region completely under King Aegon’s control.

Daemon, on the other hand, simply flies straight to Harrenhal, concluding that he and his dragon Caraxes were probably enough to take the castle by surrender. When he arrives, he learns that he was both completely right and perhaps wasted his time. The dark, dank corridors of Harrenhal are as ruined as they have been since the death of Harren the Black, and the castle doesn’t seem to offer much fighting power at all.

Harrenhal’s general lack of strength means Criston is marching toward what is essentially a worthless prize, but the allies he gains along the way are what really counts here. As you can see if you look back at the map, controlling the Riverlands for the Greens would essentially mean cutting off the Blacks’ stronghold at Dragonstone from the rest of Westeros. Sure, they can reach allies by sea, but the only nearby port for Rhaenyra is Rook’s Rest—which could be another potential Riverlands prize for Criston. But without those few cities in the region, the Blacks would be quarantined on their tiny islands and struggle to survive for long.

If this all sounds pretty grim for the Blacks, that’s because technically it is. Their side has the strongest navy, which is why Ser Corlys Velaryon sets up a blockade at the entrance to Blackwater Bay, effectively preventing supplies from reaching King’s Landing. But that’s their only real strength. However, if Daemon can somehow raise an army at Harrenhal or use his giant dragon against Criston’s forces, their fortunes could well change.

But wars are very complicated things, both in real life and in the world of Game of Thrones, and very few of them go exactly according to either side’s plan. No matter how dire the situation may seem, there are likely to be some twists and turns in the near future that keep the conflict exciting.