Imagine carrying out this order….
Basil II, the “Slayer of the Bulgars” and Byzantine Emperor from 976 to 1025, once captured 15,000 Bulgarian POWs (other sources state 8,000) and blinded 99 of every 100 men, leaving one one-eyed man in each 100-soldier cohort to lead the rest back to their ruler, Samuel of Bulgaria. Samuel was mortified by the return of his blinded army and died two days later after suffering a stroke.
More from http://www.britannica.com/biography/Basil-II:
From 986 until 1014 there was warfare between Byzantium and Bulgaria, interrupted from time to time by Basil II’s intermittent expeditions to settle crises on the eastern front. Basil II enlisted Venetian help in protecting the Dalmatian coast and Adriatic waters from Bulgarian aggression. Year by year he slowly penetrated into Samuel’s territory, campaigning in winter as well as summer. Finally, holding northern and central Bulgaria, he advanced toward Samuel’s capital, Ochrida, and won the crushing victory that gave him his byname, “Slayer of the Bulgars.” It was then that he blinded the whole Bulgarian army, leaving one eye to each 100th man, so that the soldiers might be led back to their tsar (who died of shock shortly after seeing this terrible spectacle).