The Christmas truce was a series of widespread unofficial ceasefires along the Western Front of World War I which occurred between 24 and 26 December 1914 during the Christmas holiday season. Following the indecisive Race to the Sea and the First Battle of Ypres, the Anglo-French and German forces were exhausted and informally agreed to cease hostilities for Christmas. Informal fraternizations occurred along the frontline, with soldiers from both sides exchanging gifts, having Christmas dinners together, singing carols, and even organizing a few soccer matches. The ceasefire did not last, as commanders from both sides admonished their men for temporarily ceasing hostilities, and many German soldiers who had participated in the truce were transferred to the Eastern Front to fight against the Russian Empire. The intensification and mechanization of the war (such as the introduction of gas attacks) over the next two years led to increased bitterness between both sides and the loss of interest in bilateral Christmas gatherings.