In the period Carolingio, eighth century, it was established a feudale system and Florence transformò in one county of the Sacred Roman Empire. The testimonies speak about one rebirth of the city in the Carolingio period: in the ninth century nacque an ecclesiastical public school and the bridge over the Arno, than previously had been destroyed, came reconstructed.
To the new end of the century It walls for the city came constructed, probably for fear of the invasions Hungarians. This third circle partially followed the line of the old ones Walls Roman, increasing to south in order to include the suburbs that were develop to you with pr0sperity, while to north, for political reasons, the Baptistry, Reparata Saint, the Palace of the bishop, and the adjacent Regal Palace were excluded where the representative of the Emperor held its Law court.
Towards the end of the tenth century, the Contessa Willa, vedova of the Marquis of the Tuscany, that it inside possessed an entire district of Mura, founded a Benedictine abbey, to which it donated also many moneies, to the memory of the husband. This was called “Fiorentina Abbey”.
The son of the Contessa Willa, Hugo, contributed remarkablly to the development of Florence and the decision to leave Lucca. The choice of Florence as dwelling reinforced some, in fact, the administrative character.