MacDonald, James Ramsay (1866-1937) Leader of the Labour Party between 1911 and August 1914, when he resigned in opposition to the war. Prominent anti-war campaigner between 1914 and 1918. Britain's first Labour prime minister in 1924 and prime minister again between 1929 and 1931.

Mackensen, General August von (1849-1945) German army officer who served on the Eastern Front throughout the First World War. Led German forces in successful campaigns such as the breakthrough of Russian defensive lines at Tarnow and Gorlice in May 1915; the defeat of Serbia in the autumn of 1915; and the defeat and occupation of Romania in the autumn of 1916.

Magdeburg German light cruiser that ran aground in the Gulf of Finland on 13 October 1914. From its wreck, the Russians captured a German naval signal book which greatly helped British cryptographers to decipher enemy naval messages during the war.

Mandates Territories formerly part of either the German or the Ottoman empire that were granted various degrees of independence by the League of Nations after the First World War, under the tutelage of individual Allied states such as Britain and France.

Marne River that joins the Seine on the edge of Paris, offering a barrier to armies invading France from the north. Scene of a pivotal early battle in the First World War in September 1914, which resulted in German forces withdrawing from the Marne to the River Aisne, thus destroying any chance of implementing the Schlieffen Plan. In the Ludendorff offensive of March-July 1918, the French army was driven back to the Marne, but once again the river proved to be the closest that the German army would get to Paris.

Masefield, John (1878-1967) English poet and novelist. Poet laureate, 1930-67.

Masterman, Charles (1874-1927) Head of the British government's War Propaganda Bureau during the First World War. Responsible for commissioning propaganda films such as The Battle of the Somme (August 1916).

Masurian Lakes Lakes in eastern Prussia (now NE Poland). Scene of a crushing German victory over Russian forces under General Rennenkampf in September 1914, in which 125,000 Russians were killed, wounded or captured.

Maude, General F S (1864-1917) Appointed commander-in-chief of the Mesopotamia Expeditionary Force in August 1916, presiding over the recapture of Kut-al-Amara in February 1917 and the capture of Baghdad a month later. Died of cholera in November 1917.

Menin Gate Memorial to missing Allied soldiers from the First World War, marking the wartime exit route from the Belgian town of Ypres. Opened by the king of Belgium in 1927.

Mesopotamia Former Ottoman province in SW Asia, now known as Iraq.

MI5 The name by which the counter-espionage department of the War Office was known from January 1916.

Military Service Act(s) Series of three Acts - in January and May 1916 and in April 1918 - that introduced wartime conscription in Britain and Ireland.

MilitiaVolunteer forces. In 1908 they were absorbed into the Territorial Force.

Ministry See specific name (e.g. Information, Pensions).

Mons Town in SW Belgium. Scene of the British Expeditionary Force's first engagement with the German army during the First World War (23-24 August 1914), in which the vastly outnumbered British troops were forced to retreat south towards the French frontier.

Mont Saint Quentin Fortified hill in the Albert/Bapaume area of NE France. Captured by Australian troops during the Allied counter-offensive on the Western Front (1 September 1918).

Montagu-Chelmsford reforms Series of devolutionary government and administration reforms introduced in India in 1919; named after the viceroy of India, Lord Chelmsford, and the secretary of state for India, Edwin Montagu. Also known as the Government of India Act.

Moscow, Treaty of Signed in March 1921 between Soviet Russia and Kemalist Turkey, it established a new Turkish-Soviet border and partitioned independent Armenia.

Mosul City on the River Tigris in northern Iraq. Captured by British forces in the last action of the Mesopotamia campaign (3 November 1918).

Mudros (Moudros) Port on the island of Lemnos in the Aegean Sea where Turkey negotiated and then signed an armistice with the Allies (26-30 October 1918).

Munitions, Ministry of Created during the Cabinet reshuffle in May 1915 to provide a separate ministry for controlling and organising wartime supplies. Headed until December 1916 by David Lloyd George. Discontinued in April 1921.

Murmansk Port in NW Russia on the Barents Sea. Founded in 1915; served as a base for Allied operations in northern Russia (1918-19).

Mussolini, Benito (1883-1945) Leader of Fascist Italy from 1922 to 1943. Saw active service on the Italian Front during the First World War, an experience that profoundly influenced his extreme post-war nationalism.

Muster roll List of officers and men in a particular military unit.