Spreading the news 600 years ago would have been by King's messenger, town crier, eye witnesses to battles and so on. Spreading the news now is far faster (thanks to multi media and technology) but isn't necessarily more accurate. News is still reliant on witnesses. And where you get witnesses you willl always get personal bias which can skewer what is being reported. I can't see a way around that (though it does mean the news always has a personal touch).
How is news spread in your fictional world? What are the known biases? Is the news accessible by all or only just to a privileged few? Do the journalists come from a specific background or is the news room made up from all backgrounds? Are standards high? How is the news actually reported?