The supreme command of the Army of Flanders had now been transferred to Ambrosio Spinola who proved to be a worthy opponent of Maurice. In a brilliant campaign in 1605 he first outwitted Maurice by feigning an attack on Sluys, leaving Maurice far in his rear while he actually attacked the eastern Netherlands by way of Münster, Germany. He soon appeared before Oldenzaal (only recently captured by Maurice) and the predominantly Catholic city opened its gates without firing a shot. Next he captured Lingen. The Dutch had to evacuate Twenthe and retire to the IJssel river. Spinola returned the next year and caused a panic in the Republic when he invaded the Zutphen quarter of Gelderland, showing that the interior of the Republic was still vulnerable to Spanish attack. However, Spinola was satisfied with the psychological effect of his incursion and did not press the attack. Maurice decided on a rare autumn campaign in an attempt to close the apparent gap in the Republic's eastern defences. He retook Lochem, but his siege of Oldenzaal failed in November 1606. This was the last major campaign on both sides before the Truce that was concluded in 1609.