For reasons that continue to baffle scientists and historians to this day, Western Europe enjoyed several years of high temperatures and dry weather toward the end of the 13th Century. This "Medieval Warm Period" concluded around 1300 and when the cold weather came, it brought storms and starvation with it, in an era now known as The Little Ice Age. Fortunately, the Starks were well prepared.
Martin has stated that he based the infamous Red Wedding on two actual events from Scottish history: the Black Dinner of 1440 and the Massacre of Glencoe in 1692. Asked about these events and their connection with the Red Wedding, Martin remarked, "No matter how much I make up, there's stuff in history that's just as bad or worse."
Vlad the Impaler already inspired Bram Stoker to create one of literature’s most famous monsters. Some GoT fans believe mad Vlad also served as the basis for one of GRRM’s most terrifying creations: Ramsey Snow. Both characters shared an enthusiastic love for torture and psychological torment.
Legendarily brutal ruler Attila the Hun dropped dead during his own wedding feast. Some say he choked, others say he was poisoned by someone with connections to his new wife. Certainly brings to mind the demise of a sadistic little monster we all grew to know and hate.
The two Robbs on GoT may seem to have little in common, but many believe Martin based the characters on different periods in the lives of the same king. Edward IV is said to have had a childhood similar to Robb Stark's and later ruled in the style of Robert Baratheon.
The Wall that prevents the Wildlings and White Walkers from making their way south is based on two real-world fortifications. Hadrian's Wall and the Antonine Wall may not have been quite as big and they were made of boring old stone instead of ice, but the latter is said to have housed 19 fortresses!
A real-life clash of kings, the War of the Roses was a decades-long struggle for power that pitted the Yorks vs. the Lancasters in a battle for the British throne. We feel like we've heard those warring house names somewhere before...