Queen of the Iceni is a mod that adds the following features to Civilization V:
The Celt Civilization.
Boudica, leader of the Celts.
Battle Fury, Boudica's trait, all Gun, Melee and Mounted units get 2 attacks per round.
Gaellic Warrior, Celtic unique unit that replaces the warrior and ignores terrain costs when moving.
Sons of Morrigan, Celtic unique unit that heals whenever it kills an enemy unit.
Single unit formations made up of larger, easier to see units.
Ability to disable unit buttons (toggle on the minimap menu).
Added the Mod List screen to the Additional Information menu (shows loaded mods).
Links:
Queen of the Iceni forum thread
CivFanatics - The Internets leading Civilization website
Legions Mod website
Modders Guide to Civilization V
Civilization V Wiki