Mines explodepublished at 06:28 BST 1 July 2016
Huge explosions of mines near the German lines. The main assault is imminent. And the Germans know it.
Image source, GettySummary
Battle of the Somme - as it happened
Almost 20,000 British soldiers were killed on the opening day of the battle
2,069 men from the 36th Ulster Division were killed at the Somme on 1 July 1916
All times are +1 hour BST
Picture: Attack on Thiepval, Getty Images
Mines explodepublished at 06:28 BST 1 July 2016
Image source, GettyUlster Division early in no-man's landpublished at 06:17 BST 1 July 2016
Much of the 36th Ulster Division is into no-man's land already. Fifteen minutes earlier than most of the rest of the line. "Better to be in no-man's land ready to fight, than in a trench waiting."
'Little resistance expected'published at 06:15 BST 1 July 2016
Zero hour is to be 0730 local time. Officers steel their men for going over the top. "It'll be a stroll boys."
Image source, Getty ImagesMines setpublished at 06:12 BST 1 July 2016
At the same time, tunnelers have been setting mines below the German lines.
Battering the German linespublished at 06:11 BST 1 July 2016
Around 3,000 guns have fired more than millions of shells at the Germans. Generals are convinced that the enemy lines will be devastated by this onslaught.
Image source, Getty ImagesBombardmentpublished at 06:10 BST 1 July 2016
For seven days and seven nights, Allied artillery has been pounding German lines with shells.
Image source, Getty ImagesEarly Ulster Division casualtypublished at 06:09 BST 1 July 2016
At Thiepval Wood, a box of grenades had been dropped as they were being distributed. A bomber, originally from Lurgan - Billy McFadzean - throws himself on the grenades. They explode, blowing him to smithereens. He has saved the lives of his comrades. He will be posthumously awarded the Victoria Cross.
Rum rationspublished at 06:06 BST 1 July 2016
Rations of rum were distributed along the lines during the night. Some men await their fate "blind drunk".
Waiting for the whistlepublished at 06:00 BST 1 July 2016
Zero hour approaches - troops have been gathering in trenches on the western front since 0400.
Image source, Getty Images