The portal First World War Centenary is the platform created by the Imperial War Museums, London, to bring all centenary activities concerning the First World War within the British Commonwealth together on a single website. One of the main elements is an events calendar, and a sections on news and special projects.
The website King-Emperor: The Indian Army on campaign 1900-1939 is maintained by Christopher Trevelyan. He documents the history of the Indian Army in action with a series of articles on several units of the Indian Army, numerous photographs and information about campaign medals. The website has an extensive selection of web links.
This digital collection of First World War films at British Pathé contain some 300 films concerning the First World War on a wide range of subjects. You can get small size previews on the website. Digitized versions of the original films can be ordered. The website has an advanced search mode for further research.
In April 2014 British Pathé announced the launch of 85,000 news videos at its YouTube channel. Newsreels from the period 1914-1918 can be found in this collection, too.