Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Race to the Sea is a name given to the period early in World War I when the two sides were still engaged in mobile warfare on the Western Front. With the German advance stalled at the First Battle of the Marne, the opponents continually attempted to outflank each other through north-eastern France. This brought the forces to positions prepared under British Admiralty guidance, on the North Sea coast in Western Belgium. The nature of operations then changed to trench warfare, which is very large scale siege warfare. This produced a continuous front line of trench fortifications more than 200 miles long, which by the following Spring extended from the coast to the Swiss border.