The history of Paris did not begin in France but 1500 miles to the east in the area north of the Black Sea which is now part of the Ukraine. The people who lived there were descendants of a man named Gomer and were known as the Cimmerians (Crimea is a corruption of their name). Growing in number, and continually harassed by Scythians, this race which spoke a language we now call "Proto Indo-European" split up. Some followed the largest river valley (denu) in the area from the Black Sea westwards into the Balkans. It took many decades, possibly centuries, but eventually, they reached the source of this Danube (now in Switzerland) and settled close to Lake Neuchatel. The Cwmri (Celts) who remained there became known as La Tene (the shallows). Others discovered that the sources of both the Rhine and the Rhone were only a stone's throw away. The Cwmri, if nothing else, were great traders. Hence trade routes were easily established northwards into Germany and the Netherlands. The Celts who remained near the mouth of the Rhine became the Belge or Belgie. The ones who migrated westward retained the name Gallia (Gauls). Some of these located the Seine (Sequana or snake-like river) and settled on a group of insignificant islands in the river and became known at the Parisii. Today, only two islands remain - Ile de la Cité and Ile Saint-Louis. But, originally, the Seine made a huge loop to the north - beginning where the present Canal Saint-Martin is situated, croosing what is now the Bastille, flooding the area known as Le Marais (the marsh), skirting the foot of Montmartre, and looping back to the present course. Some historians believe that the original settlement was on a knoll near Nanterre.

There was quite a thriving community of these traders still here centuries later when the Romans arrived centuries later and named the village Lutetia on Ile de la Cité. By that time, there were just four islands in the Seine. Within a few years, this tiny trading post became a major supply depot being as it was, at the highest point navigable by the sea-going ships of the time. Upstream, the Seine divided into numerous tributaries and was only redeveloped after the construction of the Canal de Bourgogne linking the Seine (via the Yonne) with the Saone, thus allowing an inland water route from the English Channel to the Mediterranean.

For the next millennium, France was little more than the Isle de France bordered on the west by Normandy, the north by Flanders and the Netherlands, the east by the Kingdom of Burgundy, and the south by the Upper Loire. Downstream, the Angevins ruled in the majestic chateaux as the Normans and Plantagenets waned and their capitals moved westward from Rouen and Orleans to Angers and Chinon. Philippe August ruled from Loches and tried to steal the lands of Richard Plantagenet while he was away at the crusades. The French eventually succeeded to some extent in the time of his brother John who was ousted from Chinon and had to retire to cold old England.

Most of the better-known Gallic Kings did not rule from Paris at all, and often never even went there. Paris was a smelly, filthy city with a population far too great for its amenities. Francois I who was a contemporary of the Tudor King Henry VIII, developed Fontainbleau as his home. Paris was retained merely as a symbolic capital (people had heard of Paris from Roman days, but who had heard of Fontainbleau?).

An important settlement for more than two millennia, Paris is today one of the world's leading business and cultural centres, and its influence in politics, education, entertainment, media, fashion, science and the arts all contribute to its status as one of the world's major global cities. According to 2005 estimates, the Paris urban area is Europe's biggest city economy, and is fifth in the world's list of cities by GDP.

Paris and the Paris Region, with €533.6 billion (US$731.3 billion) in 2007, produces more than a quarter of the gross domestic product (GDP) of France. The Paris Region hosts 37 of the Fortune Global 500 companies[9] in several business districts, notably La Défense, the largest purpose-built business district in Europe.[10] Paris also hosts many international organizations such as UNESCO, the Organisation for Economic Co-operation and Development (OECD), the International Chamber of Commerce (ICC) and the informal Paris Club.

Paris is one of the most popular tourist destinations in the world, with 45 million tourists every year in the Paris Region, 60% of whom are foreign visitors. There are numerous iconic landmarks among its many attractions, along with world-famous institutions and popular parks.

The earliest archaeological signs of permanent habitation in the Paris area date from around 4200 BC. The Parisii, a sub-tribe of the Celtic Senones, known as boatsmen and traders[citation needed], inhabited the area near the river Seine from around 250 BC. The Romans conquered the Paris basin in 52 BC, with a permanent settlement by the end of the same century on the Left Bank Sainte Geneviève Hill and the Île de la Cité. The Gallo-Roman town was originally called Lutetia, but later Gallicised to Lutèce. It expanded greatly over the following centuries, becoming a prosperous city with a forum, palaces, baths, temples, theatres, and an amphitheatre. The collapse of the Roman empire and the fifth-century Germanic invasions sent the city into a period of decline. By 400 AD, Lutèce, by then largely abandoned by its inhabitants, was little more than a garrison town entrenched into the hastily fortified central island. The city reclaimed its original appellation of "Paris" towards the end of the Roman occupation. The Frankish king Clovis I established Paris as his capital in 508.

The Black Death arrived in Paris in 1348, killing as many as 800 people a day. During this period, the population of Paris was almost 200,000. In 1466, 40,000 persons died of plague in Paris. Paris lost its position as seat of the French realm during occupation of the English-allied Burgundians during the Hundred Years' War and where Henry VI of England was famously crowned king of France in 1431, but regained its title when Charles VII of France reclaimed the city in 1436. Although Paris was capital once again, the Crown preferred to remain in the Loire Valley. In 1528, King François I shifted the center of power in France from the Loire back to the capital of Paris. During the French Wars of Religion, Paris was a stronghold of the Catholic party. In August 1572, under the reign of Charles IX, while many noble Protestants were in Paris on the occasion of the marriage of Henry of Navarre, the future Henry IV, to Marguerite de Valois, sister of Charles IX, the St. Bartholomew's Day massacre occurred; begun on 24 August, it lasted several days and spread throughout the country. During the Fronde, Parisians rose in rebellion and the royal family fled the city (1648). King Louis XIV then moved the royal court permanently to Versailles in 1682. A century later, Paris was the centre stage for the French Revolution, with the Storming of the Bastille on 14 July 1789 and the overthrow of the monarchy in September 1792. On 31 March 1814, Paris fell to the Russians—the first time in 400 years that the city had been conquered by a foreign power. The Cossack and Kalmyk cavalry units in Russian service entered the city.

Parisians revolted against the monarchy during the July Revolution of 1830. King Charles X was forced to abdicate the throne. The "February Revolution" of 1848 ended the constitutional monarchy of Louis-Philippe, and led to the creation of the Second Republic.

The Industrial Revolution, the French Second Empire, and the Belle Époque brought Paris the greatest development in its history. From the 1840s, rail transport allowed an unprecedented flow of migrants into Paris attracted by employment in the new industries in the suburbs. The city underwent a massive renovation under Napoleon III and his préfet Haussmann, who levelled entire districts of narrow, winding medieval streets to create the network of wide avenues and neo-classical façades of modern Paris. This programme of "Haussmannisation" was designed to make the city both more beautiful and more sanitary for its inhabitants, although it did have the added benefit that, in case of future revolts or revolutions, cavalry charges and rifle fire could be used to deal with the insurrection, while the rebel tactic of barricading so often used during the Revolution would become obsolete.

Cholera epidemics in 1832 and 1849 affected the population of Paris; the 1832 epidemic alone claimed 20,000 of the then-population of 650,000. Paris also suffered greatly from the siege, which ended the Franco-Prussian War (1870–1871): in the chaos caused by the fall of Napoleon III's government, the newly-established Commune of Paris sent many of Paris' administrative centres (and city archives) up in flames while 20,000 Parisians were killed by fighting between Commune and government forces in what became known as the semaine sanglante (Bloody Week).

Paris recovered rapidly from these events to host the famous Universal Expositions of the late nineteenth century. The Eiffel Tower was built for the French Revolution centennial 1889 Universal Exposition, as a "temporary" display of architectural engineering prowess but remained the world's tallest building until 1930, and is the city's best-known landmark, while the 1900 Universal Exposition saw the opening of the first Paris Métro line. Paris' World's Fairs also consolidated its position in the tourist industry and as an attractive setting for international technology and trade shows. During World War I, Paris was at the forefront of the war effort, having been spared a German invasion by the French and British victory at the First Battle of the Marne in 1914. In 1918-1919, it was the scene of Allied victory parades and peace negotiations. In the inter-war period Paris was famed for its cultural and artistic communities and its nightlife. The city became a gathering place of artists from around the world, from exiled Russian composer Stravinsky and Spanish painters Picasso and Dalí to American writer Hemingway.

On 14 June 1940, five weeks after the start of the Battle of France, Paris fell to German occupation forces, who remained there until the city was liberated in August 1944 after a resistance uprising, two months and a half after the Normandy invasion. Central Paris endured World War II practically unscathed, as there were no strategic targets for Allied bombers (train stations in central Paris are terminal stations; major factories were located in the suburbs). Also, German General von Choltitz did not destroy all Parisian monuments before any German retreat, as ordered by Adolf Hitler, who had visited the city in 1940.

In the post-war era, Paris experienced its largest development since the end of the Belle Époque in 1914. The suburbs began to expand considerably, with the construction of large social estates known as cités and the beginning of the business district La Défense. A comprehensive express subway network, the RER, was built to complement the Métro and serve the distant suburbs, while a network of freeways was developed in the suburbs, centred on the Périphérique expressway circling around the city.

Since the 1970s, many inner suburbs of Paris (especially the north and eastern ones) have experienced deindustrialization, and the once-thriving cités have gradually become ghettos for immigrants and oases of unemployment. At the same time, the city of Paris (within its Périphérique ring) and the western and southern suburbs have successfully shifted their economic base from traditional manufacturing to high-value-added services and high-tech manufacturing, generating great wealth for their residents whose per capita income is among the highest in Europe. The resulting widening social gap between these two areas has led to periodic unrest since the mid-1980s, such as the 2005 riots which largely concentrated in the northeastern suburbs.

In order to alleviate social tensions in the inner suburbs and revitalise the metropolitan economy of Paris, several plans are currently underway. The office of Secretary of State for the Development of the Capital Region was created in March 2008 within the French government. Its office holder, Christian Blanc, is in charge of overseeing President Nicolas Sarkozy's plans for the creation of an integrated Grand Paris ("Greater Paris") metropolitan authority (see Administration section below), as well as the extension of the subway network to cope with the renewed growth of population in Paris and its suburbs, and various economic development projects to boost the metropolitan economy such as the creation of a world-class technology and scientific cluster and university campus on the Saclay plateau in the southern suburbs.

In parallel, President Sarkozy also launched in 2008 an international urban and architectural competition for the future development of metropolitan Paris. Ten teams gathering architects, urban planners, geographers, landscape architects will offer their vision for building a Paris metropolis of the 21st century in the post-Kyoto era and make a prospective diagnosis for Paris and its suburbs that will define future developments in Greater Paris for the next 40 years. The goal is not only to build an environmentally sustainable metropolis but also to integrate the inner suburbs with the central City of Paris through large-scale urban planning operations and iconic architectural projects.

Meanwhile, in an effort to boost the global economic image of metropolitan Paris, several skyscrapers (300 m (984 ft) and higher) have been approved since 2006 in the business district of La Défense, to the west of the city proper, and are scheduled to be completed by the early 2010s. Paris authorities also made public they are planning to authorise the construction of skyscrapers within the city proper by relaxing the cap on building height for the first time since the construction of the Tour Montparnasse in the early 1970s.

Much of contemporary Paris is the result of the vast mid-nineteenth century urban remodelling.

For centuries, the city had been a labyrinth of narrow streets and half-timber houses, but, beginning in 1852, the Baron Haussmann's urbanisation program involved leveling entire quarters to make way for wide avenues lined with neo-classical stone buildings of bourgeoisie standing. Most of this 'new' Paris is the Paris we see today. The building code has seen few changes since, and the Second Empire plans are in many cases still followed. The "alignement" law is still in place, which regulates building facades of new constructions according to a pre-defined street width. A building's height is limited according to the width of the streets it lines, and under the regulation, it is difficult to get an approval to build a taller building.

Many of Paris's important institutions are located outside the city limit. The financial (La Défense) business district, the main food wholesale market (Rungis), schools (École Polytechnique, HEC, ESSEC, INSEAD), research laboratories (in Saclay or Évry), the largest stadium (the Stade de France), and government offices (Ministry of Transportation) are located in the city's suburbs.