The Toi pirates sailed with about 50 ships from direction of Goryeo, then assaulted Iki, Tsushima and then Hakata Bay. For a week, using Noko Island (能古島 noko no shima) in the bay as a base, they sacked villages and kidnapped Japanese people for use as slaves. The Dazaifu, the administrative center of Kyūshū, then raised an army and successfully drove the pirates away.
Three enemies were captured by the Japanese army in Matsura, but they were identified as Koreans. They said that they had guarded the borderland but had been captured by the Toi. However, Japanese officers suspected them because there had been some Korean pirates in the former Silla period. After Nakamine no Mochitaka's report, who smuggled himself into Goryeo, this suspicion was resolved. A few months later, the Goryeo delegate Jeong Jaryang (鄭子良) reported that Goryeo forces attacked the pirates off Wŏnsan and rescued about 260 Japanese. The Korean government then repatriated them to Japan. There remain detailed reports by two captive women, Kura no Iwame and Tajihi no Akomi.
These Jurchen pirates lived in what is today Hamgyŏngdo, North Korea. They frequently attacked the eastern coast of the Korean peninsula. In particular, Ulleungdo was abandoned because of their massive attacks. The invasion in 1019 was one of those incidents.