Also known as the battle of Passchendaele, this is one of the major battles of WWI. British were trying to take control of the village Passchendaele, which was located close to Ypres. The objective was to break-through, out flank the Germans and to force them to withdraw from the channel ports.
Tanks now are a very common thing to see in today's forces. However back then, they were definitively a sight to behold and fear. They were used to protect troops trying to get across no mans land. They put an end to trench warfare.
With the western front at a near standstill, the eastern front was only beginning. The main disadvantage the Russians had was their poor mobilization, meaning the could not get supplies or troops into the battle nearly as fast as the enemies could.
The Germans knew that it would take Russian troops a long time to reach Germany, so they proceeded to take over Belgium and their waffles to prevent a preemptive strike and to bolster their defenses significantly.
Germany prepared the western front for immediate attack from France. They took over Belgium in order increase their defenses. Since it would have took Russia longer to mobilize, the Germans worried about the French first.
The Archduke of Austria "Franz Ferdinand" was assassinated while he was in Sarajevo. This was one of the triggers of the first World War, mainly because tensions were high and it was bound to happen anyways because of all the nationalistic feelings each country was experiencing.
Nationalism was a very important factor in the events leading up to the first World War. When British launched their first Dreadnought, it was a clear cry of nationalism. Germany responded with their own ships, and so the race begun.