It is nearly always invisible dangers
that are most terrifying.
With these words by Julius Caesar do we get to know Vercingetorix, a Celtic tribal leader that led a revolt in Gaul against Rome in 52BC.

After defeat at Avaricum (modern France), Vercingetorix and the thousands of Celtic troops that pledged to him retreated with heavy hearts and deep concern to Gergovia, his tribe’s biggest fortified town for a last stand.
On the precipice of extinction, the Gallic tribes trembled. Many knew that if they lost, their ancient culture would capitulate forever. Others though, saw opportunity in begging Caesar’s mercy and assimilating within the conquerer’s culture.
At Gergovia Vercingetorix won triumphantly. The Celts must have been elated. Winter had come, and everyone thought Caesar would head south, back to Italy.

Although Caesar claimed that he hadn’t lost (his account is all we have of the Gallic Wars) it was apparent he’d been routed. Eventually though, in open battle, Vercingetorix was overcome by treachery within his own leadership, lack of resources and outdated war strategies.
Julius Caesar’s siege tactics, superior battle techniques, along with the full might of Rome behind him proved too much, and Celtic Gaul fell under the mighty weight in the siege of Alesia.
In Divide the Dawn, there are parodies to the rise of Rome and the fall of the Celtic world.
WhenWild Bill Lovett shows up in mysteriously Brooklyn after the Army said he died in World War I France, he immediately sees the Italian Black Hand that has him surrounded as a callback to when Caesar surrounded the Celts in Gaul.

Lovett rallies his troops to fight the Italians by telling them that he is Vercingetorix reborn, brought back to impart Celtic revenge.
Within the first few chapters, the blood runs thick. Afterward the Italian Black Hand leaders raise one of their youngest members up and task him with murdering Lovett, that man’s nickname is Scarfaced Al.