Over the following five years, the Arabs returned each spring to continue the siege of Constantinople, but with the same results. The city survived, and finally in 678 the Arabs were forced to raise the siege. The Arabs withdrew and were almost simultaneously defeated on land in Lycia in Anatolia. This unexpected reverse forced Muawiyah I to seek a truce with Constantine. The terms of the concluded truce required the Arabs to evacuate the islands they had seized in the Aegean, and for the Byzantines to pay an annual tribute to the Caliphate consisting of fifty slaves, fifty horses, and 300,000 nomismata. The raising of the siege allowed Constantine to go to the relief of Thessalonica, still under siege from the Sclaveni.