As the Livonian Brothers of the Sword after his heavy defeat against the Lithuanian Samogitians in the Battle of Schaulen (22 September 1236) in the year 1237 by arbitration of the Pope Gregory IX as Livonian Order was united with the Teutonic Knights, Dietrich von Grueningen should probably be in the same year Landmeister in Livland. However, the then Grand Master Hermann von Salza looked away from it and instead used Hermann von Balk, the Landmeister of Prussia, also in Livonia, probably because Dietrich von Grüningen only a few years earlier in the Order had come and was still very young. However, Grüningen may have already acted as representative of Balk in Livland. Already in 1238, when Balk had left because of serious illness and serious disputes with the bishop of Riga, , about the sovereign rights in the area of the former Livonian Brothers of the Sword, followed him Dietrich von Grüningen as land master in Livland.