Complex sentence: During the 19th-century Franco-Prussian War, besieged Parisians used carrier pigeons to transmit messages outside the city; in response, the besieging German Army employed hawks to hunt the pigeons.
Split into simpler sentences: During the 19th-century Franco-Prussian War, besieged Parisians used carrier pigeons to transmit messages outside the city. In response, the besieging German Army employed hawks to hunt the pigeons.