Complex sentence: His countship lasted from 1778 until 1780, and the county itself lasted from 1673 to 1806 in the central Holy Roman Empire, until it was mediatised to Isenburg.
Split into simpler sentences: His countship lasted from 1778 until 1780, and the county itself lasted from 1673 to 1806 in the central Holy Roman Empire. The county lasted from 1673 to 1806, until it was mediatised to Isenburg.