When the hour is too late for rescue it is still early enough for revenge.
-- The Buried Giant, Kazuo Ishiguro
The Buried Giant takes place in a period between Briton and Saxon wars. In real life, in an effort to reduce the brutality of existence back then, the concept of wergild was created. Under wergild, everything was given a value -- property and life were both valued -- and if you stole something, or killed someone, you were supposed to pay the price of that person to the victim or the victim's family. (Murder and manslaughter both cost the same in case you were wondering.) Generally speaking, the power elite were worth anywhere from 1 and 1/2 times to 6 times the value of a regular person; so, just like modern life.
(If you're a Tolkien fan, the One Ring was taken by Isildur as wergild.)
Wergild was supposed to replace blood revenge, which is actually a very codified form of ritual feud. Wergild in fact did replace blood revenge for a while... until Christianity came along and replaced wergild with the very Christian concept of capital punishment.
Capital punishment has always been controversial. Charles Dickens once wrote about the direct relationship between executions and increases in crime: crime goes up when public executions occur. In response to this, the British government began executing criminals behind closed doors.
Nowadays, countries in which the majority of people support the death penalty include China, South Africa... and of course the very Christian United States.