Complex sentence: His dismissal was the beginning of the end of the Cowsills as a group; the Cowsills had disbanded completely by 1972 in a storm of bitter acrimony that left some members estranged from each other for several years.
Split into simpler sentences: His dismissal was the beginning of the end of the Cowsills as a group. Shortly afterward The Cowsills had disbanded completely in a storm of bitter acrimony that left some members estranged from each other for several years.