Samaritans did not accept converts (until recently) and did not form a galut.

There was a Samaritan community in Damascus until the 1600s, shock horror, the muslims massacred them.

In the 1840s during one of the various Arab uprisings, the Samaritan community in Shechem (what the Arabs call "Nablus") were under threat of a violence which would have annihilated them for good. The chief Sephardi Rabbi of Jerusalem pleaded with the muslim authorities to spare them, claimed that they were actually Jews (Samaritans weren't even considered dhimmis under many of the muslim rulers) and with the Jews of Jerusalem, raised enough money to pay the extortion to the muslims. Ultimately this action saved them from extinction and their numbers have grown only since the modern state of Israel came to being.

Why they were targeted in the 1840s and the preceding years? Zionist occupation obviously.