Inspired by a recent TIL post that described how the pirate Captain Blackbeard treated his slaves, it got me wondering how modern historians can seemingly extract such information from little to go off of. Perhaps soldiers logs/journals told of how their superiors treated them but how accurate can that information be.
Also how common is it for modern viewpoints to flop their opinions on historic leaders based on new foundings or revelations?
At least in the case of the British Royal Navy, we have extensive records from captains and pursers covering everything from the daily motions of the ship, the events of the day (usually not eventful), the amount of food indented for and served out, the amount of supplies aboard the ship, the daily or weekly punishment logs of the men -- all sorts of information. Not all of it survives, but a captain had to cross-check and certify up to 60 sets of returns to various boards and departments in the Admiralty; if any discrepancy was found his pay was stopped until further notice. Punishment records can be surprisingly telling -- Greg Dening in Mr. Bligh's Bad Language used punishment reports to show that Bligh did not run a particularly (physically) violent ship compared to other British captains of the 18th century in the Pacific. But even less violent/gruesome reports tell many tales of interest to the historian.