Monday 4 August 2014 marked the 100th anniversary of the start of Britain's involvement in WW1
About 17m soldiers and civilians worldwide were killed between 1914 and 1918
Royal Family members and world leaders attended commemorative events in the UK and elsewhere
An international ceremony of reconciliation was held outside the Belgian city of Mons
The day's events ended with a candle-lit vigil at Westminster Abbey and "lights out" events around the UK
Other UK royals are also marking the day. The Queen will attend a service of commemoration at Crathie Kirk, external, while her husband the Duke of Edinburgh will attend a service of commemoration at Sandringham Church.
Peter Szabo in New York, US emails: My grandfather always told a story about how he was a cavalry officer for the Hungarian army during the war and how on one Cavalry charge a Russian Cossack was riding against him turned his rifle around and clubbed him off his horse. He woke up a POW in Siberia. My Grandfather was held for years but survived... not only survived but escaped once, made it all the way to St Petersburg and was recognized by an acquaintance, turned in and sent back to Siberia.
David Cameron bows his head after laying a wreath in George Square, Glasgow.
Sandra Foxton emails: Visited my great-uncle Thomas Whitehead's memorial in Arras, France, this year, found his name inscribed on the great remembrance wall. Two other great uncles (his brothers) also died in WW1 and we hope to visit their graves this year too. I don't think the young generation today have any connection with the history of WW1. It is such a shame because they probably would not be here in a free country if not for all those young brave soldiers.
Prince Charles lays the first wreath at the service in George Square in Glasgow.
Northern Ireland's First Minister Peter Robinson is in Glasgow. He said: "The key themes of remembrance and reconciliation are relevant to all of us in Northern Ireland as we continue to build a peaceful and shared society. It has often been said, but we must never forget the supreme sacrifice of so many to build a better future for us."
Meanwhile over at our @viabbc, external Twitter account, contributors all over the world are having a multilingual conversation about WW1. Shwan, a BBC Chinese weibo user says, external: In high school textbooks taught us WW1 was the unavoidable result of imperialist activities. Today's young people should realize that wars, no matter for what purposes, are bad.
At London's Westminster Abbey, orders of service and candles are being prepared for this evening's remembrance events.
Prince Harry lays a wreath at the war memorial in Folkestone.
Barbara Sigley in Cannock, UK emails: I submitted a proposal to Staffs County Council for a peace cairn to be placed equidistant between the Commonwealth and German War Cemeteries on Cannock Chase. That proposal was not taken up. During the last month I have made a peace garden at my home. The main feature is a peace cairn. I placed the first stone this morning and will add to one stone to the cairn every day until 11/11/2018. I think that is will be a total of 1265 stones.
News from 1914
The world on the brink of war
"All day long the streets of the West-end and the City were crowded with holiday folk as they never have been before…" The Times, 4 August 1914
Image source, Getty ImagesCrowds arriving in London for Bank Holiday
Crowds gather in London
The first weekend of August 1914 was a Bank Holiday in Britain.
Fearing that this was a time of "grave crisis", thousands of people travelled to London anxious to find out whether Britain would join the war.
At 19.00 on 4 August, Britain sent an ultimatum to Germany.
Christopher Mace in County Durham, England, emails: I live in Seaham, County Durham, now and after writing to The Green Jackets Museum's address asking for details on my great-great-grandfather, Joseph Ernest Mace of The 9th Service Rifles Brigade, I am spending the rest of the day - right until 11pm - at Seaham Cenotaph, which I visited on 28 June and also in Late July. I spent that last visit cleaning it of rubbish, disappointed by how it could be desecrated.
Speaking at events in Liege earlier, French President Francois Hollande said Europe could not be complacent about peace. "These men a century ago, from the depth of their heart, wished that one day all the people of Europe should be united. One hundred years later, this peace has been achieved. Europe is here, but Europe should do more, because peace is never certain, it demands vigilance, a fight, and organisations, a defence of its continents. This is why Europe should always be on the move, it should not rest on its laurels, and it should not grow tired of achieving peace."
A number of political leaders are in Glasgow today. From left to right in the front row, Glasgow's Lord Provost Sadie Docherty, Prince Charles, Prime Minister David Cameron, Deputy Prime Minister Nick Clegg and Labour leader Ed Miliband. Scottish First Minister Alex Salmond has his back to the camera on the far-right.
Image source, AFPAnother image from earlier today in Canberra - members of the Australian Great War Association pose in costume at the national war memorial.
In Glasgow, the wreath-laying ceremony is under way with a rendition of God Save the Queen.
BBC Radio 5 live
www.bbc.co.uk/5live
At 19:30 (UK time) on BBC Radio 5 live Sport Eleanor Oldroyd is joined by former England flanker, World Cup winner and keen amateur historian Lewis Moody as well as Tony Collins, Professor of History at the International Centre for Sports History and Culture at De Monfort University, to look at the impact the Great War had on sport in the UK and hear some stories of the individuals who made the ultimate sacrifice.You can watch the programme on this page, along with all other World War One programmes and clips from across the BBC, using the video carousel above. Please note that not all video and audio can be viewed outside the UK.
Image source, Sophie RaworthBBC newsreader @sophieraworth tweets, external: My grandfather captained this De Havilland DH4s in #WW1 with his lucky black cat and prayer book aged 18 #remember
News from 1914
The world on the brink of war
Image source, Shorncliffe TrustSoldiers in training at Shorncliffe Barracks, Folkestone
Folkestone prepares for war
As war took hold, Shorncliffe Barracks, just outside Folkestone, came to house thousands of soldiers on their way to the Front. Troops were partially prepared for what awaited them by a series of trenches dug into the earth for training exercises.
Image source, EPAIn Liege, military veterans carry regimental colours at the commemoration events.