Things to See in the Languedoc:   Historic Cities:   Carcassonne  (  Carcassona):   
The Saracen and Frankish periods

Saracens

Early in the 8th century, the Saracens crossed the Pyrenees from the Iberian peninsula and moved northwards, taking Carcassonne in 725 AD.   They renamed the city Carchachouna.

Franks

In 759 under Pepin the Short, the father of Charlemagne, the Saracens were driven out of Septimania and back over the Pyrénées. (A very distorted and anachronistic version of the siege provides the famous story of Dame Carcas).

The Francs introduced the Germanic tradition of building in wood.

Some authorities believe that a wooden palisade would have defended of the enceinte (stone wall), but no trace has been found - and the benefits of defending a stone wall with a wooden one are not obvious.

The defensive system of the Roman fortification did not change much. The means of attack started to improve and the first machines of war since Roman times appeared.