Throne Of Glass was written by Sarah J. Maas.
Celaena Sardothien is Adarlans greatest assassin until she gets thrown into the salt mines of Endovier to serve a life sentence. But she gets rescued by Chaol Westfall offers her a deal: She has to represent the prince in a tournament, fighting thieves and assassins to become the king´s champion. Only then she will get her freedom.
I really enjoyed reading this books especially for the fact that Celaena Sardothien is such a badass female and she´s not stupid or stuff like this. There is some kind of love triangle in that book but it´s surprisingly not that annoying so that´s ok. Also. friendship between two girls which is always super amazing.