How 'American Tolkien' George RR Martin created the world of 'Game of Thrones'

Let's take a brief look at how Martin created the world of Westeros, Essos, and so on that we have come to love. As you will see Martin was inspired by a variety of sources. 
 

Even before 'A Song of Ice and Fire', Martin had been a successful published author for two decades before he began work on the first book 'A Game of Thrones'. The series is mainly set on Westeros, which is one of the three known continents in this fictional world. On Westeros is Seven Kingdoms, which is actually only one kingdom, but called so because it was divided into seven realms some three centuries ago before the events of the series. In north, the Seven Kingdoms is bounded by the Wall, a structure built to protect the realm from threats from the frigid wastes.
 

Before 'A Song of Ice and Fire', Martin had written and published novels like science-fiction novels 'Dying of the Light' and vampire novel 'Fevre Dream'. For 'A Song of Ice and Fire', he was inspired by a variety of authors writing in diverse genres whose books he had read in his younger days. The list included HP Lovecraft, Robert E. Howard, Robert A. Heinlein, Eric Frank Russell, Andre Norton, Isaac Asimov  Fritz Leiber, and Mervyn Peake. 
 

And of course, Tolkien, like nearly every other modern fantasy author, deeply influenced Martin. With his Middle-earth, Tolkien, often referred as the father of fantasy, had basically invented fictional fantasy worlds and the genre called 'epic fantasy'. 
 

Initially, Martin had planned a trilogy of novels with around 800 pages of material per book. But the world and the plot became too big and unwieldy to really subsume everything into just three books. The plan then move to five books, and finally (as of now) to seven books. Until now, only five books have been published, with the last one 'A Dance with Dragons' being released in 2011. It has been 11 years without the next book, titled 'The Winds of Winter'.

Apart from the works of fiction, Martin took extensive inspiration from actual historical events. This is why this story feels too real and the ensuing events so tangible despite being set in another world entirely. The central event in 'ASOIAF' is War of Five Kings, which is a conflict between Houses for the Iron Throne. It was directly inspired by War of the Roses, a bloody, prolonged war that was fought between Houses Lancaster and York (notice the similarities between the words 'Lancaster' and 'Lannister' and 'York' and 'Starks'). The culture of Westeros was similar to mediaeval Europe, particularly the British Isles. For instance, culture of the southern geographical region of Westeros appears similar to mediaeval England. And the cold, rocky north with its more forbidding people looks a lot like Scotland. Similarly the continent of Essos had the Dothraki, which resembled the hordes of Mongols, the horse-lords who were as ruthless and and as difficult to defeat. 
 

Remember the Red Wedding, one of the most pivotal moments in 'Game of Thrones'? That, too, had a real-world equivalent. In the Red Wedding, many members of House Stark and their allies were killed by the Freys with the blessing of the Lannisters during a dinner at a wedding. In Red Wedding, Martin was inspired by the Black Dinner, an event in Scottish history. In the Black Dinner, members of the Douglas clan were invited to dine with King James II and beheaded under trumped-up charges. This was not a slaughter but a sentencing. But still, the motives were similarly duplicitous.
 

The Wall is a major edifice in 'ASOIAF'. As mentioned above, it protects the Seven Kingdoms from the threats beyond. Although the said threats are believed to be just wildlings, but some believe the real reason the Wall was built was to make sure the White Walkers stayed away. The White Walkers are basically ice-zombies who finally invade Seven Kingdoms in the final season of the show. The inspiration for the Wall was Hadrian's Wall. Built during the reign of Roman emperor Hadrian (thus the name), it divided the Roman province of Britannia and Scotland. 
 

Finally, the fantasy elements. Compared to the rest of fantasy, Martin's 'ASOIAF' had few of those. But dragons and direwolves did make this story a fantasy story. The dragons in this world resemble those of the European kind from the Teutonic myths. While dragons never existed (that we know of), ancient people around the world did believe they did, whether during their time or before. Direwolves in the show are simply gigantic wolves. Dire wolves (not the two words) did exist, but they were not that large, though they did outdid their modern, surviving brethren.