This week we have demonstrated that the Commonwealth is united not only by a common history - but by a common future: a future in which we work together for the benefit of all our citizens and for the wider world.
For when many of the greatest challenges we face are global in nature, the breadth of the Commonwealth – spanning six continents and a third of the world’s population – offers a unique perspective in helping to forge the global solutions we need.
No other organisation has our geographical and cultural diversity, while giving all nations an equal role, an equal voice and an equal standing.
And this week we have come together to reach a series of shared commitments that will help to build a more secure, more sustainable, more prosperous and fairer future for all.
This is the first time that security has been a central theme of our leaders’ meeting. And we have shown our resolve to stand together in defence of the rules based international system, and in defiance of those who threaten us all by seeking to undermine it.
Earlier this month the Assad regime violated international rules in the most egregious way by using chemical weapons in an indiscriminate and barbaric attack on its own people.
And while of a much lower order of magnitude, the use of a nerve agent on the streets of Salisbury here in the United Kingdom last month, is part of a pattern of disregard for those same global norms that prohibit the use of chemical weapons.
At this Summit, the Commonwealth has shown that it will play its part in a renewed international effort to uphold the global norms that say these abhorrent weapons should never, ever be used.
The Communique we have agreed today expresses our unanimous opposition to the use of these weapons – and our commitment to strengthen the effective implementation of the Chemical Weapons Convention.
We must also update our shared international norms so they can protect us from new and emerging threats online.
So we have secured the world’s largest and most geographically diverse intergovernmental commitment on cyber-security co-operation.
The Commonwealth Cyber Declaration will help protect our people and businesses from ever-more sophisticated digital threats – and counter those who would abuse the freedom of the internet to undermine our values, our security and even our democracies.
When it comes to building a more sustainable future, there are few more authentic voices than the Commonwealth, with many island states severely affected by extreme weather events and the scourge of plastics polluting our oceans.
Indeed, we are in London today because of the devastation wrought on Vanuatu by Cyclone Pam in 2015.
So as a global leader in the fight against Climate Change, we are proud that every nation of the Commonwealth has now ratified the Paris Agreement.
And every one of our nations is united behind its highest ambition of pursuing efforts to limit the increase in global average temperature to 1.5 degrees Celsius above pre-industrial levels.
At this Summit we have taken specific action to protect our oceans with the first ever Commonwealth Blue Charter.
The UK and Vanuatu are working together to launch the Commonwealth Clean Oceans Alliance to tackle the scourge of plastic pollution.
And we are already seeing a series of commitments that can mark a breakthrough in the battle to save our oceans.
For instance, Papua New Guinea has banned plastic bags…
…Belize will ban plastic bags, forks and other single use items by 2019…
…New Zealand has announced a ban on microbeads which will come into effect in June…
…The Bahamas is planning to ban plastic bags this year…
…and the UK has pledged to ban plastic straws, stirrers and plastic-stemmed cotton buds.
This is only the beginning of what will be a defining agenda for the United Kingdom’s two-year Chair in Office – and I am pleased that Prime Minister Trudeau has indicated he will also make this a priority for the G7 in Canada this Summer.
A more sustainable future also means stepping up the fight for better global health.
With over 90 per cent of Commonwealth citizens living in malaria-affected countries, the Commonwealth has a particular duty to lead international efforts to tackle this deadly disease.
So earlier this week I called on Commonwealth leaders to pledge to halve Malaria across the Commonwealth by 2023. And I am pleased that this has been agreed today.
In building a more prosperous future, this is the first Commonwealth summit to make a unanimous statement on the need to fight protectionism.
Our Declaration on the Commonwealth Connectivity Agenda for Trade and Investment will help to expand investment and boost intra-Commonwealth trade to a value of $2 trillion by 2030.
And we will play a leading role in shaping the future of global trade policy, using our unique perspective to help ensure that free and fair trade truly works for everyone.
This includes stepping up efforts to share the technical expertise to enable small and developing states to benefit from the growth of free and fair trade.
It means addressing systemic barriers to women’s full and equal participation in the economy – including increasing opportunities for women to trade internationally and supporting the growth of more women-owned business.
And it means investing in supporting our young people to gain new skills.
And at this Summit we have pledged to ensure that all girls and boys across the Commonwealth will be able to access at least 12 years of quality education and learning by 2030.
Finally, we have reaffirmed our commitment to a fairer future in which everyone is free to live their life and fulfil their potential.
We agreed the critical importance of the full social, economic and political participation of all our citizens for democracy and sustainable development to thrive.
I have been clear that nobody should face persecution or discrimination because of who they are or who they love. And the UK stands ready to support any Commonwealth member wanting to reform outdated legislation that permits discrimination, including against same-sex relations.
We will continue to protect and advance our core values of democracy, good governance and human rights at the heart of fairer societies.
And we welcomed the return of The Gambia to our family of nations.
This week has also given me the opportunity to hold a series of important meetings with Commonwealth leaders.
On Tuesday I met with the Caribbean leaders where I gave an absolute commitment that the UK government will do whatever it takes, including where appropriate payment of compensation, to resolve the anxieties and problems which some of the Windrush generation have suffered.
These people are British. They are part of us. They helped to build Britain. And we are all the stronger for their contributions.
This week began with the most inspiring gathering of young leaders from across our 53 nations.
And it is with those young leaders where the future of our Commonwealth lies.
So we were delighted to welcome the appointment of His Royal Highness Prince Harry as the Commonwealth Youth Ambassador.
Looking to that future, we have also reached an important longer-term agreement about the role of Head of the Commonwealth.
When Her Majesty the Queen assumed the throne the Commonwealth had just eight members.
Today it has 53.
We meet here today in no small measure because of the vision, duty and steadfast service of Her Majesty in nurturing the growth of this remarkable family of nations.
And on behalf of all our citizens I want to express the depth of our gratitude for everything that Her Majesty has done – and will continue to do.
Today we have agreed that the next Head of the Commonwealth shall be His Royal Highness Prince Charles, The Prince of Wales.
His Royal Highness has been a proud supporter of the Commonwealth for more than four decades and has spoken passionately about the organisation’s unique diversity.
And it is fitting that, one day, he will continue the work of his mother, Her Majesty The Queen.
As we begin the UK’s two-year Chair in Office, I look forward to working with all our Commonwealth partners in fulfilling the commitments we have made and preparing for the next meeting which we have today agreed will be held in Rwanda in 2020.
I began this week by saying that for the Commonwealth to endure, we must demonstrate our relevance and purpose anew.
Today I believe we have done that.
Our Blue Charter, our Cyber Declaration, our commitments to uphold the rules based international order, to fight protectionism, to defeat malaria, and to invest in education for all our young people…
…in all these ways and more, the Commonwealth has found its voice.
And we can look forward to a bright future with confidence.