Guilds are groups of players that join together to help each other or just fight together for glory. Guilds can be leveled to unlock Functions such as a guild bank.

Also there are guild masters that can give ships and siege gear and siege battle ships to guild members they can change the tax rate of the city and when youre in a kingdom battle you are with youre guild

The best guilds ont he game have many members but its good to try join them guilds like these are valhala (leader unknown) and shinobie (promethius)