The Germans were anxious that the British would attempt to exploit the victory of the Battle of Messines, with an advance to the Tower Hamlets spur beyond the north end of Messines Ridge. On 9 June, Crown Prince Rupprecht proposed a withdrawal to the line east of Messines. Construction of defences began but was terminated after Fritz von Loßberg was appointed Chief of Staff of the 4th Army. Loßberg rejected the proposed withdrawal to the line and ordered that the front line east of the "Oosttaverne" line be held rigidly. The (Flanders Position) along Passchendaele Ridge, in front of the line, would become and a new position, , would run west of Menin, northwards to Passchendaele. Construction of a east of Menin northwards to Moorslede was also begun. From July 1917, the area east of Ypres was defended by the front position, the (second position), (third position), (fourth position), (fifth position) and , the sixth position (incomplete). Between the German defences lay villages such as Zonnebeke and Passchendaele, which were fortified and prepared for all-round defence.