But when he was intending to cross once more to subdue the power of Gotrik, he was summoned by Leo the Pope of the Romans to defend the city.
Obeying this command, Karl intrusted his son Pepin with the conduct of the war against Gotrik; so that while he himself was working against a distant foe, Pepin might manage the conflict he had undertaken with his neighbour.

For Karl was distracted by two anxieties, and had to furnish sufficient out of a scanty band to meet both of them.

Meanwhile Gotrik won a glorious victory over the Saxons.

Then gathering new strength, and mustering a larger body of forces, he resolved to avenge the wrong he had suffered in losing his sovereignty, not only upon the Saxons, but upon the whole people of Germany.

He began by subduing Friesland with his fleet.
This province lies very low, and whenever the fury of the ocean bursts the dykes that bar its waves, it is wont to receive the whole mass of the deluge over its open plains.