Bastille Day 2017: What is it and why is it even more important this year?

American troops will join the French military to mark the centenary of the US's entry into the First World War

French President Emmanuel Macron and US President Donald Trump listen to national anthems during a welcoming ceremony at the Invalides in Paris (REUTERS/Charles Platiau)

The 14th July is an important date in the French calendar but this year the world will be watching as Donald Trump joins French President Emmanuel Macron for the celebrations.

Known in the English speaking world as "Bastille Day", France's national day marks one of the most symbolic moments of the French Revolution - the end of the regime of absolute monarchy - and had political implications which sent shockwaves through Europe.

Amidst high tensions between the citizens and the old regime in 1789, the people of Paris stormed the Bastille, a military fortress, freed the few prisoners held inside and seized weapons in the most defiant stance towards the old regime.

The day also celebrates the Fete de la Federation, which marks the unity of the French people under a common constitution, the first step towards France's modern nation.

Fireworks and village fetes are held throughout France and a military parade is held on the famous Champs-Elysées in Paris in front of the French President, officials and foreign guests.

Just before the parade, the Patrouille de France, the aerobatic demonstration team of the French Air Force, which can be compared to the Red Arrows in the UK, traditional performs, leaving traces of blue, white and red smoke in the sky.

The parade includes every division of the army and is one of the oldest and largest regular military parades in Europe.

But this year's parade will be different. About 150 American troops are expected to march besides the French military to commemorate the centenary of the US entering the First World War in 1917 as Mr Trump will watch with Mr Macron, remembering the historic tied between the two nations.

According to Le Monde, the French President first invited Mr Trump to Paris for the 14 July celebration in May during a Nato summit in Brussels but he did not receive an answer.

Mr Macron reiterated his invitation during a phone call with the US President on 27 June, following his landslide victory in the country's parliamentary elections. This time, Mr Trump said yes.

Both leaders are new to the top job in their respective countries and they are both keen to make their place on the international stage.

But in France, not everyone approves of Mr Trump's visit.

Far-left politician and presidential candidate in the last election Jean-Luc Melenchon said Mr Trump was "not welcome", while environmental activist Yannick Jadot said the visit was an "undeserving symbolic reward" to a US President who has "given a figure to humanity and the climate", France 24 reports.

Meanwhile, thousands of people are preparing to take to the streets of Paris to create a "no Trump zone" for the US President.

The Paris Against Trump alliance is planning a rally at the symbolic Place des Etats-Unis, which is the former home of the US embassy and filled with memorials commemorating ties between the two nations.

Among the group's main concerns are Mr Trump's climate change policies and travel ban.