Mijn Nederlands niet so goed is, but I try to render, with some e-tranlators, the most relevant paragraph:
It is this region that two Slavic worlds, two churches, two states come into conflict. Since the XVIe century the populace belonged to the Roman Catholic Church, but in contrast with Poland, was of the Greek-Rite... the Uniates.
Around the years 1864 the Russian persecution started against this people. Firstly certain Greek Orthodox usages were forced, under the pretense of returning to the original uniate usage. Afterwards Russian Orthodox practices were imposed. In 1874, under(?) church teacher Marcel Posuel of Khelm, through the force of the Russian officials, the Greek-Catholic diocese of Khelm became Orthodox. To the Russian state, everyone there must from now on be orthodox.
And when the population remained faithful to the Greek-Catholic church, bloody prosecution started. Firstly were taxes, ..., then exile and the jail sentences. Hundreds died..., and also in despair many killed themselves.