Conte de Deux Rois
1852
Adolph Thiers, a French politician in exile develops a fever and dies
November - A plebiscite is held to approve the restoration of the French Empire by the President of the Second Republic Louis Napoleon (nephew of Napoleon Bonaparte). 7.8 people vote in favour of the restoration while only 250,000 vote against.
2nd December - Louis Napoleon declares himself Emperor and takes the title Napoleon III
1870
War breaks out between the French Empire and Prussia. The war goes badly for the French and after Napoleon and a large French army are captured at Sedan in September, a Republican Government of National Defence is formed.
1871
January - The GND bows to the inevitable and signs an armistice with the Prussians
February 8th - Elections are held to decide the future shape of the French state.
February 17th - The Assembly meets in Bordeaux. The two branches of monarchist thought, the Legitimists and Orleanists who hold the majority of seat between them vote to restore the monarchy (In OTL Thiers, who had become a highly respected politician was mad Chief of the Executive Power of the French State)
February 20th - The National Assembly offers the crown of France to the (childless) Comte de Chambord, grandson of Charles X and Legitimist claimant to the throne on two conditions:
1. He must accept the tricolour as the flag of France
2. He must appoint the Orleanist clamaint, the Comte de Paris as his heir
February 25th - Republican members of the National Assembly led by Leon Gambetta make plain their discomfort at the possinble restoration of the monarchy.
April 10th - A delegation from the National Assembly arrives in Austria where the Comte de Chambord has lived for most of the past 40 years. They present the offer of the throne to Chambord the next day.
April 16th - After several days of deep consideration the Comte de Chambord agrees to both conditions and immediately makes plans to return to France.
May 3rd - The Comte de Chambord arrives in Bordeaux. He gives a speech to the National Assembly which is given a standing ovation by the monarchist deputies.
May 5th - The Comte de Paris arrives in Bordeaux and is offficially recognised by Chambord as his heir
June - Due to the unstable situation in northern France, Rheims the traditional place of coronation for French kings is deemed unsafe. The Bishop of Rheims agrees to travel to Bordeaux to crown Chambord.
July - The Comte de Chambord is crowned Henry V in Bordeaux. Representatives of most European countries, with the obvious exception of Prussia attend the ceremony.
Henry V makes Marshal McMahon Commander-In-Chief of the renamed Royal Army with the task of totally reorganising it after the fiasco that was the Franco-Prussian War.
1872
February - The city of Marsailles rises in revolt against the king. The city has long been a hotbed of radical politics, indeed Gambetta represented in Parliament during the Empire. The revolt is put down by troops led by a young officer, Georges Boulanger. He acts with such ferocity that he quickly becomes known as "The Butcher of Marsailles"
March - The National Assembly presents the new Constitution to the king for his approval (the irony of this is not lost upon Gambetta and the republicans.
The Prime Minister will hold limited executive power and he and his government can be dismissed by the King at any time. The declaration and prosectution of war remain in the hand of the King. At the same time elections are called for May to legitimise the new Regime.
May - In the election for the new Chamber of Deputies, Legitimists and Orleanist gain a large majority of seats. Some liberal republicans voted for Orleanist candidates reseasoning that if they the monarchist were going to run the Chamber as many Orleanist as possible should be involved. After the event in Marsailles Gambetta and the republicans were portrayed as dangerous revolutionaries but thanks to Gambetta's orartorical skills the Union Republicaine is the third largest party in the Chamber.
This is pretty much how it happened in OTL, right up to Chambord refusing the throne. The Third Republic was established as a temporary measure. It was hoped that when the Comte de Chambord died the Comte de Paris would be more amenable as far as the question of the flag. However by the time Chambord died in 1883 the Republic was too fixed in people's minds.