Ottoman cavalry in Palestine, National Library of Israel (Source: Wikipedia)
This section contains a brief introduction to the main campaigns which took place away from the Western Front, arranged by area.
The Balkans & Gallipoli
These campaigns in South Eastern Europe were about alliances: the Entente Powers sought to create access to Russia, while the Central Powers sought to link up with their Ottoman allies.
Mesopotamia & Persia
For Britain, control of Mesopotamia meant control of the land route to its Indian colonies. Persia was neutral but was the only source of oil for the British fleet. Iraq and Iran suffered.
Egypt, Palestine, Syria & Arabia
In these campaigns multi-national Entente armies drove multi-national Ottoman armies back to their Turkish homelands, while Egypt became a massive supply base.
Africa
All over Africa, British colonies fought against German colonies, using mainly colonial troops and huge corps of native carriers. However the biggest killer was disease.
Other Campaigns
The First World War was truly global. There were land engagements in Eastern Europe, the Caucasus, Italy, Serbia, Romania, the Middle East and Africa, and naval actions in every ocean.