Born into a wealthy family with Hungarian origins from Bucharest, Romania, the family relocated to the town of Berkerekul (former Yugoslavia) when Renczi was ten. By the age of fifteen, she had become increasingly unmanageable by her parents and had frequently run away from home with numerous boyfriends, many of whom were significantly older than herself. Early childhood friends described Renczi as having an almost pathological desire for constant male companionship and possessing a highly jealous and suspicious nature. Although Vera Renczi was a stunningly beautiful woman (according to the standards of the time, I guess), she was also one of the most prolific female serial killers in history, driven by a pathological need for devotion from men.

Renczi's first marriage was to a wealthy Bucharest businessman many years her senior and she bore him a son named Lorenzo. Left at home daily while her older husband worked, she began to suspect that her husband was being unfaithful. One evening, in a jealous rage, Renczi tinctured the man's dinner wine with arsenic and began to tell family, friends, and neighbors that he had abandoned her and their son. After approximately a year of "mourning", she then declared that she had heard word of her supposedly estranged husband's death in a car accident

http://theunexplainedmysteries.com/Vera-Renczi-Black-Widow.html