Homicide is the killing of another human being. It is not necessarily unlawful.
Homo sapiens has killed his fellows as long as there have been records, e.g. there is evidence of human induced fatal fracturing of the skull in 43,000 BC. However, homicide rates have declined a 100-fold in the last seven centuries. In Europe in the 14th century the homicide rate has been estimated to be 100 per 100,000. The current rate is now 1 per 100,000.