Cornelius Tacitus, Germany and its Tribes
Alfred John Church, William Jackson Brodribb, Ed.

The Angrivarii and Chamavi are bounded in the rear by the Dulgubini and Chasuarii, and other tribes not equally famous. Towards the river are the Frisii, distinguished as the Greater and Lesser Frisii, according to their strength. Both these tribes, as far as the ocean, are skirted by the Rhine, and their territory also embraces vast lakes which Roman fleets have navigated. We have even ventured on the ocean itself in these parts. Pillars of Hercules, so rumour commonly says, still exist; whether Hercules really visited the country, or whether we have agreed to ascribe every work of grandeur, wherever met with, to his renown. Drusus Germanicus indeed did not lack daring; but the ocean barred the explorer's access to itself and to Hercules. Subsequently no one has made the attempt, and it has been thought more pious and reverential to believe in the actions of the gods than to inquire.