These women weren't afraid to get their hands dirty. Welcome to WatchMojo, and today we’re counting down our picks for the most infamous cases where a woman was alleged to have killed either one or multiple romantic partners.

We hope you never had a run-in with any of these infamous criminals. For this list, we’ll be looking at the worst Irish criminals in history, including those from the Republic of Ireland, Northern Ireland, and Ireland before Partition.

¡Top 10 PEORES MADRES de la Historia! Suscríbete: https://www.youtube.com/user/watchmojoespanol Desafortunadamente, hay muchas malas madres en la historia, pero algunas se pueden clasificar como las peores del planeta. Entre Casey Marie Anthony, quien esperó un mes para reportar la muerte de su hija a las autoridades; Mary Ann Cotton, quien probablemente mató a tres maridos y 11 de sus hijos; y Susan Smith, quien ahogó a sus dos hijos al hundir su automóvil en un lago, hay muchas madres terribles por ahí. En honor al Día de la Madre, WatchMojo te presenta el Top 10 de las Peores Madres de la Historia. Sugiere tus ideas: http://watchmojo.com/sugerencias Facebook: http://www.facebook.com/WatchMojoEspanol Twitter: http://www.twitter.com/WatchMojoEs

Unfortunately, there are many bad moms in history – but some can be categorized as the worst mothers on the planet. Between Casey Marie Anthony, who waited a month to report her daughter’s death to authorities, Mary Ann Cotton, who likely killed three husbands and 11 of her children, and Susan Smith, who drowned her two young kids by driving her car into a lake, there are more than enough notoriously terrible mothers out there. In honor of Mother’s Day, WatchMojo introduces you to ten famous bad mothers.