King Calenhad Theirin once famously declared, "The fate of Redcliffe is the fate of all Ferelden." Certainly, the castle is the first and last defense for the sole land route into Ferelden, and the country has never fallen to any force that did not first capture Redcliffe.
The castle, which despite being three times captured is popularly described as "unassailable," also guards one of the largest and most prosperous towns in Ferelden. Redcliffe village is well situated near the mountain pass to Orzammar and the Orlesian border, and so serves as a center of foreign trade. For these reasons, Redcliffe is accounted an arling despite the smallness of the domain.
The inhabitants of Redcliffe village are primarily fishermen or merchants who ship dwarven goods through the pass from Orlais to Denerim. When the entire village smells of smoked fish on certain late autumn mornings, the merchants in their finery do their utmost to pretend otherwise.
The events of the Fereldan civil war left Redcliffe in tatters. Its reconstruction has been a slow process, but the city has made a remarkable recovery after its ordeal at the hands of young Lord Connor Guerrin.
After the Battle of Denerim, Arl Eamon gave the arling over to his younger brother in order to devote his full attention to advising the throne. He left the new Arl Teagan with the monumental task of rebuilding the town and perhaps the even greater challenge of dealing with the influx of mages into the area following the breaking of the Circles.
—From The Changing Face of Thedas by Sister Petrine, Chantry scholar