The seat of the Prince of Monaco was established on the Rocher de Monaco (Illustration 5) as a fortress in 1191 when the harbour, that is today lined by Monte Carlo, was acquired by the Republic of Genoa. The harbour and its immediate area were given to the Genoese by the Emperor Henry IV with the proviso that the Genoese protect the coastline from piracy. Further territory was ceded to the new owners by the Council of Peille and the Abbaye de Saint Pons. In 1215 work began on a new fortress, comprising four towers connected by ramparts protected by a curtain wall. This forms the core of the present palace.