Who served out the longest prison sentence known to history? My extensive investigation – begun in 2010 but now comprehensively updated – answers that question [it’s Charles Fossard, of Australia, with an all-but-incomprehensible 70 years, 303 days]. It also takes a look at some of Fossard’s unwitting and unwilling rivals, and tries to go inside the cells, to hear from the prisoners themselves. Their stories are often brutal, occasionally pathetic, but always surprisingly compelling.

The full story – which includes numerous case studies, a state-by-state listing of the longest sentences served everywhere from Alabama to Wisconsin, a look at record stretches from elsewhere, some notes on extraordinary cases of protracted solitary confinement, and a listing of all 16 known cases of men who spent in excess of 60 years behind bars – can be read here.