The Tui Tonga decline began due to numerous wars and internal pressure. In the 13th or 14th century, the Samoans had expelled the Tongans from their lands after Tu'i Tonga Talakaifaiki was defeated in battle by the brothers Tuna, Fata and Savea, progenitors of the Malietoa family. In response, the falefā was created as political advisors to the Empire. The falefā officials were initially successful in maintaining some hegemony over other subjected islands but increased dissatisfaction led to the assassination of several rulers in succession. The most notable were, Havea I (19th TT), Havea II (22nd TT), and Takalaua (23rd TT), who were all known for their tyrannical rule. In AD 1535, Takalaua was assassinated by two foreigners while swimming in the lagoon of Mu'a. His successor, Kauulufonua I pursued the killers all the way to Uvea, where he killed them.