Complex sentence: They were selected among landowning families of that county, with preferential voting done by the four estates of each counties, and could not register in multiple precincts--a restriction which was met with public protest by some of the boyars.
Split into simpler sentences: They were selected among landowning families of that county, with preferential voting done by the four estates of each county. They also could not register in multiple precincts--a restriction which was met with public protest by some of the boyars.