In the year of our Lord 1251, immediately after Easter [Apr 16], those of Fivelgo and Hunzingo gave each other hostages and renewed their alliance; and with the help of those of Menterne[1] they laid siege to Groningen. Some crossed the ramparts, and climbed on ladders and started to fight them manfully. The Groningers defended themselves for a long time with stones and trebuchets, expecting that the Frisians would, according to their customs, soon return to their own region. But when the Frisians had maintained their siege for four weeks, the Groningers began to fear that, when the city would be taken by force, an enormous carnage would take place. Therefore they surrendered themselves in the hands of the enemy. The Frisians set the condition that the walls would be destroyed, and that the stonehouses would be pulled down till the storage rooms; the traders were allowed to keep living there with their possessions, but the knights would have to leave the city with their life and property, and would never be allowed again to have a residence there. And so the the walls were leveled for the largest part and the houses were lowered. The knights resided that year on the other side of Coevorden[2], where it was possible. Also the fortification of Peize was destroyed.
[1] Menterne: Frisian shire East of Fivelgo.
[2] Castle guarding the Southern moor pass of Drenthe
[3] Peize: village to the SW of Grongingen, where the Van Groningen clan had a castle.
