A Song of Ice And Fire takes place across two continents, Westeros and Essos. In these regions, seasons last for years. It has been summer for many years, but winter is approaching, and the turn of the season also triggers many momentous events. There are three distinct storylines, although they are ultimately interconnected.
Many centuries ago, the Seven Kingdoms that ruled Westeros were united under the powerful Targaryen Dynasty, who had the service of fire-breathing dragons at their disposal. This dynasty came to an end when the dragons apparently became extinct.
There was a power struggle over the Iron Throne, once held by the Targaryens and the last Targaryen ruler was killed in a rebellion led by Robert Baratheon.
Now, after Robert's death, his young son, the cruel and self-absorbed Prince Joffrey, occupies the throne, supported by his mother and her powerful family, the Lannisters. The northern fiefdoms in Westeros are held by the powerful Eddard Stark, who swears allegiance to Robert Baratheon.
In the far northern border of Westeros, there is a huge, centuries old Wall of Ice. This is the only barrier that protects Westeros from the unearthly beings called the Others. And, there are the Wildlings, humans who live beyond the wall. This Wall is protected by the sentinels of the Night's Watch.