'Honour killings' happen all over the world and are committed by people of all religions and have a history that goes back as far as human history in general.
For example:
"As noted by Christian Arab writer, Norma Khouri, honor killings originate from the belief that a womans chastity is the property of her families, a cultural norm that comes "from our ancient tribal days, from the
Hammurabi and Assyrian tribes of 1200 B.C."
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Matthew A. Goldstein, J.D. (Arizona), has also noted that honor killings were encouraged in ancient Rome, where male family members who did not take actions against the female adulterers in their family were "actively persecuted".
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The origin of honor killings and the control of women is evidenced throughout history in the culture and tradition of many regions. The
Roman law of
pater familias gave complete control to the men of the family for both their children and wives. Under these laws, the lives of children and wives were at the sole discretion of the men in their family. Ancient Roman Law also established historical roots of honor killings through the law stating that women found guilty of adultery could be killed by their husband in whatever manner the husband desired. In ancient Rome, being raped was seen as dishonorable to the point of destroying a woman's life and reputation, and honor killing was supposed to be a "merciful" act.[
citation needed]In Greece also, the lives of women were dictated by their husbands as females were considered socially below males.
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Among the
Amerindian Aztecs and
Incas, adultery was punishable by death.
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Qays bin Asim, ancient leader of
Banu Tamim is credited by some historians as the first to kill children on the basis of honor. It is recorded that he murdered all of his daughters to prevent them from ever causing him any kind of dishonor.
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http://en.wikipedia.org/wiki/Honor_killing#In_history
To simply write the concept off as 'Islam' is, at best, ignorance.