✡ From a note in Beitzah 4b:
There non-Jewish residents of Cutha were brought by the Assyrian king, Shalmanesser, to settle the parts of the Eretz Yisrael left desolate by the exile of the 10 Tribes. Although they converted to Judaism, the validity of their conversion was the subject of considerable dispute. They reminded a sect onto themselves – known as the Samaritans because they lived in Samaria – and exhibited animosity towards the Jews.
Huh! I had no idea that was the origin of the Samaritans. Cool factoid.