Elantris by Brandon Sanderson
Elantris was built on magic and it thrived. But then the magic began to fade and Elantris began to rot. And now its shattered citizens face domination by a powerful Imperium motivated by dogged religious views. Can a young Princess unite the people of Elantris, rediscover the lost magic and lead a rebellion against the imperial zealots? Brandon Sanderson's debut fantasy showed his skill as a storyteller and an imaginer of baroque magical systems to be fully developed from the start.