The Race to the Sea was a series of intended flanking maneuvers by Western Front antagonists during the early days of World War I.

German forces had invaded Belgium in early August of 1914. The German high command had envisioned a quick victory, but the conquest of neutral Belgium took longer than expected. Forces from France and the United Kingdom joined in to fight alongside Belgium, in that country and in France. The German successes continued, for the most part, in the Battle of the Frontiers, but a determined Allied defense at the First Battle of the Marne and then a determined counterattack at the First Battle of the Aisne had convinced the German commanders to try a series of flanking maneuvers in order to continue in the vein of the Schlieffen Plan and envelop the opposition. Allied forces had the same idea, and the two sides traded inconclusive attacks for a few weeks, until they ran out of land, reaching the North Sea coast of Belgium in mid-October.

Since neither side had turned the corner on the other, it was left to staking pitched battles, and so the opposing armies threw themselves at each other at the concurrent Battle of the Yser and First Battle of Ypres. The latter lasted longer, ending on November 22. By that time, both sides were exhausted, physically and mentally. One thing had changed, however. The German high command had ordered its troops to dig trenches, in order to fortify the positions that they already had. Their enemies would do the same.