Complex sentence: As of 1855 Saint Clair's family does not own the Lithuanian mansion anymore, based on one version-due to sale, based on another-due to confiscation by Russian imperial authorities as retaliation for treacherous activity.
Split into simpler sentences: As of 1855 Saint Clair's family did not own the Lithuanian mansion anymore. Based on one version it was sold while based on another it was confiscated by Russian imperial authorities as retaliation for treacherous activity.