Michael Palaiologos found himself faced with a powerful coalition that, according to the Byzantinist Donald Nicol, "seemed likely to threaten the possession not only of Thessalonica but even of Constantinople itself". Michael Palaiologos did not tarry. Already in the autumn of 1258, his army crossed over into Europe, under his brother John Palaiologos, who held the quasi-imperial rank of , and the (commander-in-chief) Alexios Strategopoulos, and wintered in Macedonia, where it was joined by local levies. At the same time, Michael Palaiologos sent separate embassies to each of the three main allies, hoping to pry them apart by diplomacy. These efforts failed, as the three allies stood to gain much from a successful offensive against Nicaea.
