The largest landowner group at the end of the thirteenth century was the: church kings merchants barbarians

merchants

Explanation:

Kings actually didn´t have that many lands for themsleves, and the church didn´t either, so the ones that actually have large lands were the merchants, who were starting to become the "new rich" this means that they were little by little accumulating wealth. The barbarians didn´t actually figure in this period of time since the barbarians weren´t formally organized.

pretty sure they split up because of religious conflicts.

mark other guy brainliest