Westeros is the land across which the Seven Kingdoms were first divided, then brought under Targaryen rule, and repeatedly tested by war, famine, disease, and disputes over inheritance. Its decisive significance lies in the tension between a realm claimed as one and a land whose distances, regional powers, and competing histories keep that unity incomplete. Even the calendar reflects this tension: the maesters date events from Aegon I Targaryen’s coronation, not his landing, although the conquest unfolded over years and Dorne remained unsubdued long afterward.

A divided realm and the making of a kingdom

In Aegon’s youth, Westeros comprised seven rival kingdoms, with conflicts between two or three of them rarely absent. The North was ruled by House Stark; Dorne by House Martell; the Westerlands by House Lannister; and the fertile Reach by House Gardener. House Arryn held the Vale, the Fingers, and the Mountains of the Moon. The Storm Kings of House Durrandon had once ruled a much larger eastern territory, but their power had been reduced by pressure from neighboring kingdoms. In the riverlands, Harren the Black ruled as King of the Isles and the Rivers, his long reign marked by the construction of Harrenhal beside the Gods Eye.

The geography and political divisions were intertwined. The Stormlands had lost lands to the Reach, Dorne, and the ironborn; Harren’s family had taken the Trident from earlier river kings and extended its domains eastward. Westeros was therefore not a settled group of provinces awaiting a single ruler, but a contested landscape in which borders and authority had been repeatedly remade by force.

Aegon’s conquest did not begin and end on a single date. His landing at the mouth of the Blackwater Rush preceded his coronation at the Starry Sept in Oldtown by two years, and the major battles had already been fought before the anointing that later became the accepted start of his reign. The distinction mattered to the chronology: much of the actual conquering took place before the dating era called After the Conquest began. The crowned king styled himself ruler of the Seven Kingdoms even though Dorne had not submitted. With his sisters, he had brought the kingdoms together under one authority, but the title expressed an aspiration as well as an accomplished fact.

Rule, alliance, and the limits of unity

Aegon’s government sought to make political unity visible in daily life. Former enemies were encouraged to send younger children to court, where boys served as pages, cupbearers, and squires, and girls as handmaidens and companions to the queens. In King’s Landing, they encountered royal justice and were encouraged to think of themselves as subjects of a single realm rather than of separate regions. The court thus served as a meeting place for the families whose lands had been conquered.

Marriage also became a means of binding those lands together. Aegon’s queens arranged matches that crossed regional boundaries: Ronnel Arryn married a daughter of Torrhen Stark, and the heir to Casterly Rock wed a Redwyne from the Arbor. Queen Visenya arranged a double marriage between House Blackwood and House Bracken, long-standing rivals, to help secure peace between them. These alliances treated kinship as political infrastructure: a tie between houses could link communities that conquest alone had not reconciled.

The effort to extend royal power into Dorne showed how little a title could accomplish by itself. After negotiations with Princess Meria Martell failed, the Targaryens launched a campaign across the passes. Aegon entered through the Prince’s Pass while Orys Baratheon led troops into the Boneway. Dornish forces avoided a pitched battle, withdrew, and denied the invaders supplies. Crops were burned, wells poisoned, and mountain routes made dangerous. Aegon’s army faced shortages as it crossed the high passes; Lord Harlan Tyrell’s force suffered from heat and the loss of water and horses, while Orys’s column was trapped and defeated in the Boneway. Aegon took several strongholds, but the campaign’s uneven results made plain that military superiority could not erase the advantages of local terrain and strategy. Dorne remained outside the realm, and attempts to subdue it continued beyond Aegon’s reign.

Inheritance, conflict, and regional power

Later struggles over the Iron Throne drew force from the same regional and dynastic divisions. The Dance of the Dragons, fought from 129 to 131 AC, had roots in the succession questions and crowded family claims that developed during the long reign of Jaehaerys I Targaryen. When Prince Aemon died, Jaehaerys named Aemon’s brother Baelon heir, passing over Aemon’s daughter Rhaenys and her unborn child. The Great Council of 101 AC later chose Viserys Targaryen over Rhaenys’s son, Laenor Velaryon. Its decision was widely understood to establish a precedent against a woman inheriting the Iron Throne or transmitting that claim to her male descendants. The realm’s political order was thus shaped not only by conquest but by precedents that determined which branches of the royal family could claim authority.

Westeros’s roads, rivers, passes, and weather continued to determine the course of conflict. During the Dance, Borros Baratheon attacked the riverlords on a rain-soaked road near King’s Landing. The soft ground disrupted his cavalry charge, while archers and a shield wall held the route; additional river forces then emerged from nearby woods. The encounter, known as the Battle of the Kingsroad and by its fighters as the Muddy Mess, ended as a one-sided defeat for the stormlanders. Terrain did not merely frame the battle: mud, the narrow road, the adjoining hill, and the wood shaped what each army could do.

The Vale offered another example of how distance and terrain could change a campaign. A force under Ser Robert Rowan struggled through deep snow and repeated attacks in the high passes. On the way, its men disturbed Sheepstealer, and the brown dragon fled farther into the mountains with Nettles on its back. By the time the survivors reached the Bloody Gate, a third of the force had died from attack, cold, or hunger. Their arrival brought them shelter and food, but not the military strength their allies had expected. In Westeros, a host could reach its destination and still be diminished beyond usefulness by the journey.

Hardship, memory, and the connected realm

Seasonal catastrophe could also cross regional boundaries. The winter of 59–60 AC struck the North first and hardest, but failed harvests and rising food prices reached the riverlands, Westerlands, Vale, and even the Reach. As food grew scarce, the Shivers spread into Westeros from the east, moving across Blackwater Bay and up the Blackwater Rush. Port towns were thought to be especially vulnerable. Smallfolk suspected that ship-borne rats carried the disease, though the Citadel did not establish that cause; cats became so sought after that kittens could sell for as much as destriers. The illness was swift and often fatal, while the maesters could describe its course but had no known cure. The episode links the realm’s regions through trade and travel as surely as royal policy did, showing that danger could move along the same routes that connected distant communities.

Events far beyond the royal succession likewise had consequences across Westeros. When the Rogare Bank collapsed in Lys, lords and merchants discovered that money entrusted to the family was lost. In King’s Landing, Lotho Rogare was arrested as he tried to leave, and Lord Roggerio Rogare was taken into custody; in Gulltown, Moredo Rogare surrendered his command and sailed for Braavos. The trials and penalties that followed revealed how a crisis originating across the Narrow Sea could reach creditors and political figures throughout the Seven Kingdoms.

Westeros is therefore both a political whole and a collection of places whose differences remain consequential. Royal marriages and institutions sought to bind its peoples together; dynastic precedents defined who could rule; roads and mountain passes could determine whether armies arrived intact; and winter or contagion could cross borders without regard for allegiance. The repeated attempt to make seven kingdoms one never removes those local conditions. They are the means by which unity is built, challenged, and sometimes exposed as incomplete.