Once this citadel is breached, the other walls can come tumbling down.
They severed the last railroad lifeline into Atlanta, making the citadel of the Confederacy as it was touted no longer tenable.
It turns out that Santorum has a deep connection to the citadel.
1580s, "fortress commanding a city," from Middle French citadelle (15c.), from Italian cittadella, diminutive of Old Italian cittade "city" (Modern Italian citta), from Latin civitatem (nominative civitas; also source of Portuguese citadella, Spanish ciuadela; see city).