The two brothers closely collaborated in the subsequent years. According to the "Illuminated Chronicle", they together worked out a military strategy against the Germans, who were frequently invading the kingdom in the early 1050s. Ferenc Makk writes that Béla's epithetsthe Champion or the Wisentare connected to his fighting against the Germans. The chronicler emphasizes that Andrew and Béla "lived in a great tranquillity of peace" even after Andrew fathered a son, Solomon, in 1053. Béla was one of the lords witnessing the deed of the foundation of the Tihany Abbey, a Benedictine monastery that his brother established in 1055.