She poisoned 21 people including her own mother, children and husbands. So why has no-one heard of Britain's FIRST serial killer, Mary Ann Cotton?

Few have heard of the so-called ‘Black Widow’ killer who posed as a wife, widow, mother, friend and nurse to murder perhaps as many as 21 victims, living off her husbands before eventually claiming their estates. Two decades before Jack the Ripper would terrorise the streets of Whitechapel in London, Mary Ann Cotton had already become a killing machine, perhaps murdering as many as eight of her own children, seven stepchildren, her mother, three husbands, a lover – and an inconvenient friend.

http://www.dailymail.co.uk/femail/article-2096423/Britains-serial-killer-Mary-Ann-Cotton-She-poisoned-21-people-including-MOTHER-CHILDREN-HUSBANDS.html