He remained with the corps through 1917, where it fought at the Third Battle of Ypres, and into 1918, where it began the year holding an exposed salient on the boundary between Third and Fifth Armies. It was heavily attacked in Operation Michael, the first phase of the German spring offensive of March 1918, and both it and the neighbouring VII Corps were forced to retreat, leaving a gap in the British lines. The responsibility for this was a matter of historical dispute for some decades, but the response at the time was unambiguous; both Fanshawe and the commander of VII Corps, Walter Congreve, were removed from command.