on the settlements of the Venetian lagoon in 810 by Pepin, the
son of Charlemagne, created an historic shift in the residential pattern
of the lagoon dwellers.
Frankish forces quickly seized Chioggia at the south end of the lagoon
and then Palestrina, the southernmost of the major barrier islands
that protect the lagoon from the Adriatic. Malamocca, the Venetian
capital and one of the most populous of the Venetian islands, lay
next in its path.
between Palestrina and Malamocco ultimately proved to be Pepin's Waterloo
and the point where his advance was stymied. While the issue remained
in doubt, however, the capital was removed to a more protected group
of islands near the center of the lagoon. That area was known as Rivo
Alto, or "Ri'Alto" [high bank], because the islands were sedimentary
banks of the Brenta River delta, whose mouth lay several kilometers
to the west. Many Venetian families also removed to Ri'Alto, seeking
the protection afforded by the treacherous shoals that lay between
Ri'Alto and the invaders.
After the Frankish
threat had passed, the capital remained at Ri'Alto, together with
a concentration of the new residents. In later years, the population
of Ri'Alto grew rapidly, its land area expanded dramatically by landfill
behind rows of pilings. The area at Ri'Alto soon became the metropolitan
center of the lagoon, the city known today as Venice. "Rialto" survives
as the name of the commercial area that surrounds the oldest bridge
on the city's Grand Canal, which is itself the vestigial river bed
of the Brenta River.