The offensive began at on 14 October, with an attack by the GAF from the
Lys river at
Comines northwards to
Diksmuide. The British
creeping barrage advanced at a rate of per minute, much faster and much further than the practice in 1917, in expectation that there would be little resistance from German infantry. By the evening the British forces had reached high ground which dominated
Werviq,
Menen and
Wevelghem in the south; further north the British captured
Moorslede and closed up to
Gulleghem and
Steenbeek. Belgian troops on the left reached
Iseghem, French troops surrounded
Roulers and more Belgian troops captured
Cortemarck. Roulers fell the next day and by 16 October, the British held the north bank of the Lys up to
Harelbeke and had crossed the river at several points. By 17 October,
Thourout,
Ostend,
Lille and
Douai had been recaptured;
Bruges and
Zeebrugge fell by 19 October and the Dutch border was reached the following day. The crossing of the Lys and the capture of
Courtrai by the British Second Army on 19 October, led to a German retreat on the front of the Fifth Army further south, which encircled
Lille on 18 October. The next day the British were in
Roubaix and
Tourcoing and by the evening of 22 October, the British had reached the Scheldt from
Valenciennes to
Avelghem. ==Aftermath==