Often, history is written by the victor. More often it’s written by the survivors, who may or may not be the victors. More often than that, it’s written decades or generations later by someone with an agenda.

As a result, it’s wise to be skeptical of the “lessons of history” and to pay more attention to verifiable facts and a wider range of views. “History” also changes, depending on who’s presenting it, as one can easily see by looking at the versions of U.S. history presented today by those with different views and agendas.

This has been the case throughout history. The battle at Kadesh in 1274 BCE, between the Egyptians and the Hittites, was a bloody and brutal draw, but Ramses II had celebratory inscriptions of victory chiseled into stone all over Egypt. It wasn’t until the last 50 years or so, with the discovery of the massive clay tablet library in the ruins of the Hittite capital of Hattusas, that historians were able to sort out what really happened.

For generations, there was a widely held view that Europe suffered the “dark ages” from the time of the fall of the Western Roman Empire in the fifth century CE until roughly the Renaissance. Except… it didn’t. What it did suffer was a massive fragmentation of governance. Later, the term “Middle Ages” was adopted, but there was still a perception of darkness and plagues, even though the Roman Empire also suffered darkness, anarchy, and plagues.

Recent archeological studies have shown, for example, that after the Romans withdrew from England, very little changed in people’s everyday lives over the next few centuries. The same was true in France under the Merovingian kings. Fewer massive buildings and roads were constructed, most likely because smaller kingdoms couldn’t muster the resources, especially when there was more local warfare.

In the United States, as everywhere, history has often been distorted or “revised.” Historical revisionists have persistently claimed that the Civil War was not about slavery. This persistent myth claimed the war was fought over states’ rights or economic differences, but in reality, the protection and expansion of slavery was the central cause of the Confederacy because the entire economy of the south was based on slavery. After reconstruction, a set of lies permeated the south portraying the Confederacy as a noble and heroic cause and whitewashing the history of slavery and elevating Confederate leaders like Robert E. Lee to undeserved heroic status.

In the mid-1930s Hitler and other right-wing German nationalists propagated the false claim that the army had not been defeated on the battlefield, but that it was betrayed by enemies on the home front – specifically Jews, Marxists, and other leftists, who undermined the war effort and forced the military to surrender, an agenda designed to shift blame away from the military and the politicians.

History is messy and multifaceted, and to come close to understanding any period takes a great deal of study, which is why most people go with generalizations that often bear more resemblance to what they want to believe than to what actually occurred.