The interesting thing about the Lombards is that we know a whole lot more about them once they completely integrate with the old Roman Senatorial Class than we do know before. And that is to say, not a whole lot.

The most complete somewhat contemporary account of the Lombards is Paul the Deacon, a cleric active at the very end of the Lombard Kingdom in Italy (there's also the earlier L'Origo Gentis Langobardorum, but Paul himself dismisses it as a ridiculous fable. Then there's the Succinta de Langobardorum gentis historiola on which Paul bases his history, but only twelve lines have been transmitted down to us). Paul was by all means an in intelligent and well-respected intellectual: when the Lombard kings were deposed by Charlemagne, Paul successfully petitioned for the release of a number of his relatives who had been taken hostage, and even earned a reputation for his eloquence in Latin. Paul subsequently settled in the abbey of Montecassino, where he wrote a number of works, including Historia Langobardorum. In the Historia, Paul affirms that in the original Lombard language "Lang" means "Long" and "Bart" means "Beard."

Now, Paul seems like a great guy, but that translation strikes me as a little too convenient. Bart means "Battle Ax" in Old High German, a language similar to the one the Lombards would probably have spoken; so if you want to believe the Lombards called themselves, "Those With the Battle Axes," you can be my guest; there is close to nothing left passed down to us about what the Lombard language might have sounded like to lead us favor that or Paul's explanation.

As early as the first century, there are records of Roman writers (including Tacitus) talking about a tribe of "Langobardi," which could indicate that there already was a tribe somewhere in Germany calling themselves something that sounded more or less like that. There was even a region in northern Germany called Bardowick which might betray a common Germanic etymological origin. So even if they didn't call themselves "Long-Beards," they probably called themselves something that sounded like that to Latin listeners.