Quoted from Sparky:A Song of Ice and Fire series (Game of Thrones is book one) by George R. R. Martin.
I love this book series and I'm currently on my second read through, but I personally don't recommend anyone start these unless Martin finishes the series. "The Winds of Winter" is years behind with a "possibly 2018" release date. Then after that he still has "A Dream of Spring". I don't think he'll ever finish them.