Conversation so far:
what is the last book in game of thrones
The Winds of Winter is the planned sixth novel in the epic fantasy series A Song of Ice and Fire
when will The Winds of Winter come out
George RR Martin Expects 'Winds of Winter' To Be Released By July 2020.
who wrote The Winds of Winter
The Winds of Winter is by American writer George R. R. Martin.

Question: how did the author come up with the idea for the book series
Self-contained rewrite: how did George RR Martin come up with the idea for Game of Thrones