laid siege to Thessaloniki in 614–616. However, that particular event was actually of local significance. A combined effort of the Avars and Slavs two years later also failed to take the city. In 626, a combined Avar, Bulgar and Slav army besieged Constantinople. The siege was broken, which had repercussions upon the power and the prestige of the Avar khanate. Slavic pressure on Thessaloniki ebbed after 617/618, until the Siege of Thessalonica (676–678) by a coalition of Rynchinoi, Sagoudatai, Drougoubitai and Stroumanoi attacked. This time, the Belegezites, also known as the Velegeziti, did not participate and in fact supplied the besieged citizens of Thessaloniki with grain. It seems that the Slavs settled on places of earlier settlements and probably merged later with the local populations of Greek descent to form mixed Byzantine-Slavic communities. The process was stimulated by the conversion of the Slavic tribes to orthodox Christianity on the Balkans during the same period. A number of medieval sources attest to the presence of Slavs in Greece. En route to the Holy Land in 732, Willibald "reached the city of Monemvasia, in the land of Slavinia". This particular passage from the Vita Willibaldi is interpreted as an indication of a Slavic presence in the hinterland of the Peloponnese. In reference to the plague of 744–747, Constantine VII wrote in the 10th century that "the entire country [of the Peloponnese] was Slavonized". Another source for the period, the Chronicle of Monemvasia, speaks of Slavs overrunning the western Peloponnese but of the eastern Peloponnese, together with Athens, remaining in Byzantine hands throughout the period. However, such sources are far from ideal, and their reliability is debated. For example, the Byzantinist Peter Charanis believes the Chronicle of Monemvasia to be a reliable account, but other scholars point out that it greatly overstates the impact of the Slavic and Avar raids of Greece during this time. Max Vasmer, a prominent linguist and Indo-Europeanist, complements late medieval historical accounts by listing 429 Slavic toponyms from the Peloponnese alone. The extent that the presence of the toponyms reflects compact Slavic settlement is a matter of some debate and might represent an accumulative strata of toponyms, rather than being attributed to the earliest settlement phase. Relations between the Slavs and the Greeks were probably peaceful apart from the (supposed) initial settlement and intermittent uprisings. Being agriculturalists, the Slavs probably traded with the Greeks inside towns. Furthermore, the