In military terms, a salient is a battlefield feature that projects into enemy territory. Therefore, the salient is surrounded by the enemy on three sides, making the troops occupying the salient vulnerable.
The Ypres salient was formed by British, French, Canadian and Belgian defensive efforts against German incursion during the 1914 "Race to the Sea", culminating in the Battle of the Yser and the First Battle of Ypres.
These battles saved the Ypres salient and the corner of Belgium around Veurne from occupation, but also led to the beginning of trench warfare in the salient as both sides "dug in" around the line. The area of the salient is mostly flat, with few rises or hills. Those that did exist became the focus for the 1915 Second Battle of Ypres, which saw the first use of gas and the almost total destruction and evacuation of Ypres, as well as extensive tunneling prior to the Battle of Messines in 1917 and the Third Battle of Ypres at Passchendaele in the same year.
After the third battle, the Ypres salient was left relatively quiet until the Fourth Battle of Ypres, the Battle of the Lys, when the Spring Offensive threatened to overwhelm the entire area. This offensive was stopped at the point the Allies were closest to being forced to abandon the salient. By August 1918, the Fifth Battle of Ypres (part of the Hundred Days Offensive) pushed the German forces out of the salient entirely and they did not return.
- Dendooven, D and J Dewilde, The Reconstruction of Ieper - A walk through history Openbaar Kunstbezit in Vlaanderen 1999 ISBN 90-76099-26-X
- Holt, T and V, Major and Mrs Holt's Battlefield Guide to the Ypres Salient Leo Cooper Pen and Sword 2003 ISBN 0-85052-551-9