List of serial killers before 1900

The following is a list of serial killers i.e. a person who murders more than one person, in two or more separate events over a period of time, for primarily psychological reasons A serial killer is most commonly defined as a person who kills three or more people for psychological gratification; reliable sources over the years agree. See, for example:
 * who began committing their crimes before 1900. This list does not include mass murderers, spree killers, war criminals, or members of democidal governments. This list is chronological by default, but can be re-ordered using the button at the top of each column.
 * who began committing their crimes before 1900. This list does not include mass murderers, spree killers, war criminals, or members of democidal governments. This list is chronological by default, but can be re-ordered using the button at the top of each column.
 * who began committing their crimes before 1900. This list does not include mass murderers, spree killers, war criminals, or members of democidal governments. This list is chronological by default, but can be re-ordered using the button at the top of each column.
 * who began committing their crimes before 1900. This list does not include mass murderers, spree killers, war criminals, or members of democidal governments. This list is chronological by default, but can be re-ordered using the button at the top of each column.
 * who began committing their crimes before 1900. This list does not include mass murderers, spree killers, war criminals, or members of democidal governments. This list is chronological by default, but can be re-ordered using the button at the top of each column.

Unconfirmed serial killers
The existence of the following serial killers is dubious or contradicts the accepted historical record: