longest world champion reign ever cc for answer

[SimonH]

Longest reign should really be measured in title defences..

..not years.

Whom would that be?

Some dudes are fighting 4/5 times a year whilst other only fight 3 times a year if that..

Then it is:

Mr Saengmuangnoi Lukchapormasak aka Samson Dutch Boy Gym, Samson Kratingdaen-Gym, Samson Toyota-Thailand, Samson 3-K Battery, Samson Elite Gym was 39-0 in WBF title fights (38 defences of his 115lbs crown)