During the reign of Charlemagne, no serious effort was made to establish a permanent mission in Denmark or Sweden. Louis le Debonnair had more zeal or better opportunities; and he readily sanctioned the departure of Ebbo, archbishop of Rheims. Ebbo was a Saxon, and more eager for the conversion of the kindred Danes than any of the French prelates. Encouraged by a papal bull, he ventured on the perilous enterprise in 822. Fortunately for him, Harald, surnamed _Klak_, who ruled over a portion, at least, of Jutland, had need of imperial aid to secure himself on the throne. As the condition of such aid, he agreed not only to become a vassal of the empire, but to embrace Christianity, and do all in his power to make his subjects embrace it. The court of Harald was near the present city of Sleswic, in the duchy of that name. Ebbo, accompanied by the monk Halitger, proceeded thither, and was permitted by the royal consent to preach to the people. But the fortunes of Harald were diversified; he was expelled three or four times, and as often enabled to return, as much through foreign assistance as through the efforts of his own partisans. That he was unpopular may easily be inferred from these revolutions in his fortunes. Of this unpopularity one cause was doubtless his profession of the new faith; another was the homage which he had paid to the emperor. Yet the efforts made by the kings who reigned in Zealand to create a monarchy, and consequently to destroy the Reguli, who aimed at independence, was, doubtless, more injurious to his interests, than the disaffection of the pagans. But during his intervals of peace, his patronage of Christianity was serviceable to the cause. Ebbo naturally left the country when the king was expelled; and there was danger of the good seed being choked, when another and more zealous missionary was raised by divine Providence both to continue the work which he had begun, and to extend it to Sweden. [Sidenote: 826 to 830.]