The Battle of the Somme, which was fought in the Somme river valley in northern France, began on July 1 1916 and was a day of disaster for the British.
Around 100,000 Allied men went over the top to attack the German lines.
By the end of that first day, almost 20,000 British soldiers were dead, making it the worst day in the history of the British Army.
Men from Huddersfield and from across the West Riding fought and died during the Somme offensive.
Local regiments which took part included the Duke of Wellington's, West Yorkshire Regiment, King's Own Yorkshire Light Infantry and the Prince of Wales' Own West Yorkshires.
The 100th anniversary will be marked with events across the country.
Bells will toll for five minutes from 7:30am on Friday, July 1, at churches across Yorkshire and beyond.
Many churches across Huddersfield are taking part and a special civic and community service will be held in Ravensknowle Park at 2pm on Friday, July 1.