The book is based mainly on 'primary' sources rather than secondary sources.
a new 'primary school' [=('US') 'elementary school', ('US') 'grade school']
The 'primary' function of our schools is to educate our young people.
(..) You said you'd marry me. And I meant it. When I was a bastard named Snow. What I want is no longer the primary consideration. I'm furthering a dynasty. Do you think she's pretty? Of course I do. I'm not blind. (..)2015 TvShow: Game of Thrones Title: Kill the Boy Season: 5 Episode 5