Rain Wild Chronicles Series by Robin Hobb

The Rain Wild Chronicles is a 4-book fantasy series by Robin Hobb, published 2009–2013. It is part of the larger Realm of the Elderlings universe and follows the return of dragons and a dangerous expedition to the lost Elderling city of Kelsingra.

Total 4 Books - 

1. Dragon Keeper - Malformed dragons hatch along the Rain Wild River, and unwanted youths are assigned as their keepers. They begin a risky journey upriver seeking the lost Elderling city where the dragons might thrive.

2. Dragon Haven - The expedition continues as humans and dragons struggle with survival, leadership conflicts, and harsh environments. Relationships deepen while hopes of reaching the ancient city grow uncertain.

3. City of Dragons - Some dragons finally discover the buried city of Kelsingra and begin reclaiming it. Meanwhile, political tensions, romance, and rival interests threaten both humans and dragons.

4. Blood of Dragons - Kelsingra rises again as dragons gain strength and independence. Human keepers must choose their futures while outside forces converge, leading to battles, alliances, and a new dragon era.