 In 88 AD, Silla built two forts named Gaso (가소성, 加召城), and Madu (마두성, 馬頭城), to guard against the encroachment of the Kingdom of Baekje and the Gaya confederacy, respectively.This led to the start of tensions with Gaya.It was not until 94 AD that Gaya initiated hostilities against Silla.