Dr Harold Shipman, ( 1946 - 2004 )
Another example of the ways in which good old British determination and grit enable us to hold a World record.
In Shipman's case, he is almost certainly the record holder for most one-on-one murders, and thus tops the serial killer charts.
His tally is put somewhere between 215 (lowest official estimate) and a possible career best of 479.
They played the long game, and will be remembered for eternally.