That's where the leaders of the six founding members gathered on March 25, 1957 to sign to the Treaty of Rome establishing the European Economic Community, the predecessor of today's EU.
Many milestones have gone in to paving the long road to European unity. Mario Segni likes to recall a certain dinner in Paris a few weeks before the Rome meeting.
From Soup To Nuts
It was early 1957, and Segni's father, then-Italian Prime Minister Antonio Segni, had taken the 17-year-old student along with him for the ride to the French capital. There, with the heads of France, Belgium, Germany, the Netherlands, and Luxembourg, the elder Segni hashed out the details of what would become the basis of European unity.
"I remember it well because, as a high school student, I accompanied my father to Paris," Segni says. "[The meetings] lasted three days and it was not the formal act, but it was the substantial act [of the Treaty of Rome]. I have very vivid memories of that, even though I was just a student then and didn't handle these issues. I remember that dinner in the embassy with [German Chancellor Konrad] Adenauer."
A few weeks later, on March 25, the same leaders signed the Treaty of Rome, establishing the European Economic Community, a customs union or common market based freedom of movement of goods, services, capital, and people.
In reality, the free movement of people and capital would have to wait a few decades. But the treaty did quickly establish a free movement of goods, a gradual reduction of tariffs and a common agricultural policy -- all of which would lead, incrementally, to the rest.
A Closer Union
Indeed, lodged in the spirit of the treaty lay a larger dream, one that would take time to realize.
It was articulated in the preamble, which stated that the EEC members were "determined to lay the foundations of an ever closer union among the peoples of Europe."
"[The treaty] was considered as a step, as an instrument, toward political integration," Mario Segni explains. "The signatories, or least the Italian government -- my father, [then-Italian Foreign Minister Gaetano] Martino -- and certainly the Germans strongly desired to arrive at a sort of United States of Europe. And they were convinced that through this instrument, through first a customs and then an economic union, they would eventually get there."
That gradualist approach was the brainchild of Jean Monnet, the French civil servant whom many consider the architect of modern Europe.
As a member of the French government in exile, Monnet had written in 1943, in the midst of World War II: "There will be no peace in Europe if the states rebuild themselves on the basis of national sovereignty."
Monnet had helped Europe take its first step toward integration. The European Coal and Steel Community, set up by the 1951 Treaty of Paris, was largely his creation. Its purpose was to make another European war impossible by pooling the industrial resources of the six member states. In the process, economic development would be spurred.
On May 9, 1950, then-French Foreign Minister Robert Schuman announced the plan. The date of Schuman's Declaration, considered the real beginning of what is now the EU, was later selected to be celebrated as Europe Day.
"In taking upon herself for more than 20 years the role of champion of a united Europe, France has always had as her essential aim the service of peace," Schuman said. "A united Europe was not achieved and we had war. Europe will not be made all at once, or according to a single plan. It will be built through concrete achievements, which first create a de facto solidarity."
Faltering Early Steps
The coal and steel community, which also included the creation of the European Commission, the bloc's executive arm, led to calls for an immediate political and defense union, including a European army. Those efforts failed in 1954, when the French parliament rejected them, largely out of fears of surrendering too much sovereignty.
Similar concerns are also what kept Great Britain out of the Treaty of Rome, which also created an atomic energy community.
But Britain would join the EEC in 1973. Britain's membership was long opposed by France's Charles De Gaulle, who saw London as a potential U.S. Trojan horse.
But Segni and others say Britain's entry helped pave the way for the gradual enlargement of Europe to 27 nations.
"My father was certainly a strong supporter, years later, of the United Kingdom's entry," Segni says. "I've found later, in De Gaulle's memoirs, a very clear a description of the meeting of the heads of state and foreign ministers in which he, De Gaulle, recalls being pushed to the sidelines. He mentions in particular the speeches by Antonio Segni and [Paul-Henri] Spaak, the Belgian foreign minister."
One other often ignored fact of the Treaty of Rome is its creation of the European Court of Justice, which New York University historian Tony Judt -- author of "Postwar: A History Of Europe Since 1945" -- actually calls the treaty's "only truly significant innovation."
"My father was absolutely conscious of the importance of this fact - of the importance of this fact, that this [the creation of the European Court of Justice] would create European law, that it would be the first step in the creation of European rights, and thus that this would be an extremely strong tool for building [a united Europe,]" Segni says.
After 1957, the road to today's EU would pass many more milestones, including the 1992 Maastricht Treaty, which led to political and monetary union and the name European Union, and the 2004 enlargement that added 10 mostly former communist countries.
But when EU leaders gather in Berlin this weekend to celebrate Europe's birth, they'll know that all roads lead to Rome.