AT 11pm on August 4, 1914, Britain declared war on Germany.
This was the last major act in a chain of declarations following the murder of Archduke Ferdinand on June 28.
A month later, Austria-Hungary invaded Serbia; Russia then declared war on Austria-Hungary; Germany declared war on Russia; France declared war against Germany in fulfilment of its treaty obligation to support Russia, and the British Empire became involved after Germany violated Belgium neutrality.
As Sir Edward Grey, Foreign Secretary, stood at a window in the Foreign Office following the German invasion of Belgium, he famously remarked: "The lamps are going out all over Europe. We shall not see them lit again in our time."
The British Cabinet voted unanimously to declare war on Germany the following day.
To remember that momentous declaration as part of a worldwide vigil, there will be a 'Lights Out' event at St Philips Church in Webheath on Augist 4 at the close of the first day of its World War One exhibition, from 5-10pm.
A spokesman said: "We will extinguish candles during the vigil as we remember Sir Edward Grey's words, and the events that followed."
Redditch Council will also be taking part in what promises to be the hugely poignant ‘Lights Out’ event.
All external and internal lights at the town hall in Walter Stranz Square, Alcester Street, will be switched off for an hour from 10-11pm on August 4.
Lights Out is a headline project of the cultural programme 14-18 NOW and was initiated by the Department for Culture, Media & Sport.
Every member of every community in the UK is invited to take part in Lights Out bringing their own personal thoughts and reflections to the occasion.
For more information on Lights Out go to 1418now.org.uk/whats-on/lights-out.