 There are notes of Swedish churchmen, possibly led by Finland's bishop Thomas, being present in Tavastia ca 1230, and papal letters deplored how slowly Christianity gained ground in Finland.There was apparently a backlash against the missionaries (the Häme insurrection), and in 1237, Pope Gregory IX sent out a call for the Swedes to take up arms in a crusade against the "apostates and barbarians".All details of the crusade are from "Eric's Chronicle", which is largely propagandist in nature, written a century after the events, amidst internal unrest and a war against Novgorod.