There are also a number of user-created factions, several of which are grouped together in downloadable "Eras." For example, the Imperial Era includes the Roman-influenced Lavinians, the Marauders, and the Wild Elves, featuring completely new unit trees and abilities. An alternative era, which contains the Islam-influenced faction Khalifate, was integrated (as of 6 January 2014) in the official development line, Wesnoth 1.11.8, tested to become part of the mainline version. However, it is quite possible to create factions that can be used in the default eras, though the amount of blessing given by the creators for each may vary.