The world of A Song of Ice and Fire spans two vast continents - Westeros, a feudal landmass divided into the Seven Kingdoms, and Essos, a diverse continent of free cities, ancient civilisations, and vast grasslands to the east. The story takes place in an era of political upheaval following a rebellion that overthrew the three-hundred-year Targaryen dynasty, replacing it with a fragile new order that quickly fractures into civil war. The world is defined by its unpredictable seasons - summers and winters that last years or even decades - and by the growing threat of the Others, an ancient enemy stirring beyond the great ice Wall in the far north. Magic, long thought faded from the world, begins to return as dragons are reborn and old powers awaken. George R.R. Martin began the series in 1996 with A Game of Thrones, originally planning a trilogy that has since expanded to a planned seven volumes, five of which have been published. The series has sold over 90 million copies worldwide and was adapted into the HBO television series Game of Thrones (2011–2019).