The Treaty of Rome was signed on March 25, 1957, cementing an economic agreement between six European countries that ultimately paved the way to today’s European Union.

On that spring day, France, Belgium, Italy, Luxembourg, the Netherlands and what was then West Germany agreed to a customs union, aiming to create a single market for goods, labour, services and capital across all member states. They formed the European Economic Community (EEC), rooted in the idea that open, tariff-free trade would make every member better off.

60 years on from Rome, the EEC is the EU, a bloc of 28 member states who cooperate on everything from trade to counter-terrorism to tourism.

While there is no way of knowing how Europe would have fared without the EU in place, the last six decades have been a time of unprecedented peace and prosperity for a continent with a long history of bloodshed.

At a time when Brexit and a wave of Euroscepticism pose serious challenges to the EU, here is a look back at some of the major achievements of the past 60 years.

1. It gave 500 million people the freedom to live, study or work anywhere

Freedom of movement is one of the major principles of the EU’s common market - and one of the more contentious, with fears over immigration feeding into a populist backlash. However, it is worth remembering that in the EU today over 500 million people enjoy the right to live, study or work in any of the EU’s 28 member states. Around 14 million EU citizens live in a different country, according to statistics from 2014.

The EU also created the Schengen Area, a zone of passport-free, borderless travel that covers over 400 million people. Most EU members are part of Schengen, along with some non-EU countries - namely, Iceland, Norway, Switzerland and Liechtenstein. Schengen means you can theoretically get on a train in Vilnius and get off in Valencia without having to show your passport. Although some border controls have been reinstated in the wake of the refugee crisis and terrorist attacks, the agreement is still in place.

2. It created one of the world’s biggest single markets

Along with labour market mobility, the free movement of goods, services and capital has made the EU one of the biggest single markets in the world. Major waves of expansion in 2004 and 2007 brought 12 new countries, mostly from central and Eastern Europe, into the fold. The GDP of the European Union last year was $16,5 trillion according to the IMF, representing 22.8% of the world’s total.

On an individual level, if a consumer in France wants to order a pram from Poland or a coffee machine from Italy, she doesn’t need to worry about import tax. On a broader level, ease of doing business provides a major economic boost. It’s impossible to quantify precisely because European integration took place alongside broader trends in globalization, but economists agree that removing barriers to trade creates wealth.

“Of course this is profitable for the private sector as they seek to increase their operations across the EU, which in turn offers a wide array of choice to EU consumers at competitive prices. However there are still some standards, rules and practices which remain at the national level and are still not harmonized. There are good hopes for progress though, in particular with the digital space,” said Francesca Bianchi, a specialist in Trade and Investment at the World Economic Forum.

3. It won the Nobel Peace Prize in 2012

The Nobel committee honoured the EU because it had “for over six decades contributed to the advancement of peace and reconciliation, democracy and human rights in Europe".

For a country to join the EU, it needs to meet three criteria: political, with stable institutions underpinning democracy; economic, with a functioning market economy; and legal, with the acceptance of EU law and practice. Under this process, a number of former dictatorships and ailing ex-communist economies made peaceful transitions.

On the global stage, over half of all development aid comes from the EU and its members.

4. It banished the death penalty

In 1983, the European Convention on Human Rights was updated with a new protocol to abolish the death penalty. Although this wasn’t directly the EU’s work, the lure of joining the bloc played a key role in ending capital punishment in Europe. To join the EU, a country first joins the broader Council of Europe, a human rights organisation. No country can join the Council of Europe unless it ends the death penalty first.

5. It built a 1.23 million-ton butter mountain

Even the most ardent of Europhiles will agree that the EU’s Common Agricultural Policy (CAP) has been a contentious and complicated affair. To support struggling farmers in the Eighties, the EU provided guaranteed prices for agricultural products, creating notorious mountains of butter and lakes of wine and milk. The EU’s sugar policy also led to criticism, notably from Oxfam in 2002, for providing export subsidies to European refiners that meant farmers in poor countries couldn’t compete. The EU is currently phasing out export subsidies.

6. It took sewage off Europe’s beaches and ratified the Paris Agreement

Clear blue: EU law made bathing beaches clean up their act

The EU has the biggest programme of environmental legislation in the world, including setting standards for swimming water that forced many beach resorts to tackle sewage. Last year, it ratified the Paris Agreement to limit global CO2 emissions. As Emily Farnworth, Head of Climate Change at the World Economic Forum, explained:

“The European Union was a powerful driving force in securing international agreement on climate change. Being able to speak as one united voice, rather than 28 single voices, helped cut through during climate negotiations – big markets are hard to ignore.

The EU has established the first major carbon market and agreed ambitious emission reduction, energy efficiency, and renewable energy targets through its climate-energy packages, first for 2020 and now for 2030.

The Habitat Directive is another good example – for 25 years, it has been protecting Europe’s biodiversity across the region. It recognises that effective approaches to conservation need to take account of the natural environment rather than political boundaries.”