Well the thing about him is that he was really in the early stages of inventing history. To read back our modern conceptions of bias is to be quite anachronistic. In essence, Herodotus reported what he heard, what he saw, and what he rationalized had happened. He specifically points out that he's just reporting, not investigating. This is why we see that in his histories, the reportage generally gets less and less accurate as you get further from Greece (see him talking about there being giant ants in India). So while there are certain parts that are inaccurate, 1. it wasn't really his goal to exclude information he thought is wrong (he says that he doubts several accounts that he relates) and 2. bias and accuracy hadn't really been formulated as concepts yet.

I'd recommend reading it though because The Histories are totally awesome and really exciting.

Much like the previous post said before me, Herodotus’ Histories were created as an experiment of history in a time of new intellectualism. And yes it was also clear that he wrote about what he heard when he was staying in Halicarnassus, a major trade port of the ancient Greek world. Herodotus likely wrote his history by ear because it was hard to travel around the ancient world to the places he wrote about. While he probably had the money to travel, it was still a dangerous thing to do in Mediterranean and the Levant because of robbery and piracy. With all that said, some Greeks, Ionian or not, were attempting to write histories about the world but not like the history Herodotus wrote.

Though Herodotus was one of the best surviving histories of the Pre-Roman Mediterranean from the Greek Archaic Period, it was clear from the commentary in anthologies of the ancient world and of late antiquity world that there were other histories like Herodotus’. These were histories that were written about more specific subjects, works that were written more like Aristotle’s works. There were some that covered a decent amount of historical berth but most did not cover as much as Herodotus did. But yes he does have some inaccurate parts of his book because he romanticized some certain parts of his book and shelled out his opinions in other parts. But there is a bigger message to be taken out of Herodotus’ Histories most people don’t see. This book was being read by the people of Ionian, Ancient Greece, and the Mediterranean world directly after it was written and was accurate to them.

There is evidence of the Athenian agora or market having booksellers that were just printing copies of Herodotus for people to buy amongst other books like The Persians by Aeschylus and Homer’s Iliad. Ancient historians know this is the case because the Cambridge translation by Robin Waterfield consists of multiple copies complied together from many different ancient publishers. So it was clear that this was getting read and while his book may not be the complete truth, it was information the Greek people were interested in. And the reason why we still use it as a source today and give it some precedence as a creditable source is because it lasted throughout time. This may not seem like a big deal initially but multiple copies surviving the chaos of the ancient world is phenomenal. It was a world full of chaos and war that included the destruction of many Greek households where copies were used and kept. Along with the burning of the Library of Alexandria, where most copies existed besides in the ones in Library of Pergamon. The fact that Herodotus’ book survives throughout the ancient world and was saved by the Romans, Byzantines, and the Ottomans showed that Herodotus’ tome had some creditable value to the ancients.

This book had value at the time and throughout time because it was the first book to include facts from Persia, Scythia, Egypt, the Levant, and Greece. This was something he was able to do because he lived in a Greek Ionian polis that lived under Persian rule and had time to write a history. This was not something other Greek aristocrats had time to do because they were involved with more governmental work and fighting, something the people of Halicarnassus were never forced to do. Secondly, he lived in an area where he would hear stories and facts from a wide variety of people because the Ionian Coast was a place full of merchants from all over the Mediterranean. So while Herodotus in parts is inaccurate to us, we need to remember it was accurate enough for the people of the ancient Mediterranean world because historical events were generally presented orally, much like the old epics of Homer. Greek people knew their local history orally and it was only during this time that major historical works started getting written down. This is why Herodotus should be given his due because he started writing down things he heard and put them into historical context.

Though even after knowing all of this, it is important to use a critical mind when analyzing Herodotus and using him for historical research. Solely because he was an investigator of history in his time and not a true historian in our eyes. It is the ancient historian’s job to use his tome liberally to answer questions of the ancient world, rather than making his work the true history of his world. So when reading Herodotus, remember he is not always right on facts or how events played out, but he generally pretty accurate about Greek cultural ideas and their reactions towards the Persians.