Many of the Northern Ireland fans set to flock to France for Euro 2016 will be aware of the historical connections between Ireland and some of the regions they will be visiting.
Echoes of both world wars of the 20th century redound in the area around Paris, while Lyon and the south coast, the Riviera, played a now little-known part in the liberation of the country in 1944-45.
In August 1944, Allied troops, mainly American and French, landed west of Nice in Operation Dragoon. Their plan was to advance northwards through the Rhone valley towards the Vosges mountains.
Commanding VI US Corps, which had fought at Anzio, was Major General Lucian Truscott Jnr. Truscott has a unique place in American military history as the only officer to have commanded at regimental (brigade), divisional, corps and army levels during the Second World War.
Intended to command the Fifteenth Army in France, Truscott was transferred to Italy to succeed Mark Clark as commander of Fifth Army and led that formation in the final campaign in northern Italy.
The finest American field commander in the European theatre, Truscott was of Irish descent and fought those last battles in Italy alongside Lieutenant General Sir Richard McCreery, commander of the British Eighth Army, whose family were rooted in Killyclogher, Co Tyrone.
The visitors to Nice and the Riviera generally will have some sense of the difficulties facing the Allies as they landed in southern France, although there are few relics of the Second World War that can be seen there today.
However, as the football fans travel north towards Lyon and Paris, they will see many more signs and memorials of both world wars, especially in and around Lyon.
One of the most beautiful of French cities, Lyon lies in an idyllic setting, with the Rhone and Saone rivers converging almost in the city centre to form the Presqu'ile, a peninsula.
A Unesco World Heritage Site, Lyon has a traumatic history from the Second World War. On September 3, 1944, it was liberated jointly by the 1st Free French Division and the FFI, the French Resistance.
During the occupation, Lyon became a stronghold for the Resistance. The visitor can still see the secret passages - the "traboules" - used by locals and the Resistance to escape raids by the Gestapo, the German secret police.
The most notorious German officer in Lyon was SS Hauptsturmfuhrer (Captain) Klaus Barbie, the "Butcher of Lyon". Responsible for the brutal torture of many French civilians, including women and children, Barbie is reckoned to have been involved in the deaths of as many as 14,000 people. In spring 1944, he ordered 44 children in an orphanage to be deported to Auschwitz.
Barbie also took part in direct operations against the Resistance and arrested Jean Moulin, one of the main Resistance leaders. He was awarded one of Germany's highest decorations, the Knight's Cross with Oak Leaves, for his anti-Resistance work.
Not until 1987 was Barbie brought before a court in Lyon for his crimes - protected by the Americans immediately after the war, he fled to Bolivia. Sentenced to life imprisonment, he died in Lyon in 1991 from leukaemia.
Lyon has a museum of the Resistance, which is worth a visit in a city of many and varied attractions.
Moving on to Paris, the travelling fan will pass through more territory that was fought over in August 1914 as German armies threatened the City of Light.
Within days of declaring war, the United Kingdom despatched an Expeditionary Force to support the French and Belgian armies, but the speed and weight of the German advance forced the defenders into an exhausting fighting retreat.
The Germans intended to sweep around Paris and force the French government to surrender. However, the stoic courage of French poilus (infantrymen), assisted by British Tommies, stalled the German advance.
The British force was outnumbered greatly by their French allies and their German opponents, and it is hard to credit that both French and German forces suffered casualties of more than 20,000 men in a single day during this period.
As exhausted soldiers strove to stop the advancing Germans, there were many acts of great bravery. The first Victoria Cross (VC) of the war was earned by a young Irish officer of the Royal Fusiliers (City of London Regiment) at the Nimy bridge over the Mons canal on August 23, 1914.
Lieutenant Maurice Dease, from Mullingar, Co Westmeath, was killed in action that day during the Battle of Mons, but was posthumously awarded the VC. He is buried in St Symphorien Military Cemetery in Belgium. His unit was fighting a rearguard action as British troops retreated alongside their French allies.
The German plan to sweep around Paris and roll up the French armies came to naught. But this clash of huge armies, equipped with the weaponry of the industrial age, meant that many thousands lost their lives.
In the First Battle of the Marne, from September 5-14, 1914, the German advance on Paris was fought to a standstill and then counter-attacked.
The Germans were close to the eastern outskirts of Paris, their objective almost within their grasp, but a stout defence and a determined counter-attack by six French armies and two British corps (basically a small army) forced the attackers to begin a withdrawal. That withdrawal led to the First Battle of the Aisne, from September 13-28, in which the Allies followed up the retreating Germans, but, in turn, found the German defence increasing in strength.
Eventually, on September 28, the French commander called off the offensive. Both sides had fought to exhaustion.
What few realised at the time was that the war of movement was all but over. Before long, the opposing armies were digging in and, as the autumn days shortened, their trenches were deepened and soon were stretching from the Channel coast to the Swiss frontier.
Before the year was out, the First Battle of Ypres saw a costly attempt to break the stalemate. It was a stalemate that would persist for more than three years.
It is a sign of the nature of the First World War that some of the final actions of the war were fought not far from the first actions. Irish soldiers were involved in both and Irish dead from 1914 are to be found close to Irish dead of 1918.
As Euro 2016 progresses, a new page of sporting history will be written for both Irish teams. Thankfully, it will be a page without the horror and death of those pages written by other young Irishmen a century ago.
Richard Doherty is the author of Churchill's Greatest Fear: The Battle of the Atlantic - 3 September 1939 to 7 May 1945 (Pen & Sword Military)