The Pope, the Queen, Nelson Mandela & Obama–what do they have in common?

LONDON (CNN)–With all the pomp and pageantry that Britain could muster President Obama Wednesday made history as the first American president to stand in London's Westminster Hall to address both Houses of Parliament.

He began on a lighter note saying, "I am told that the last three speakers here have been the Pope, Her Majesty the Queen, and Nelson Mandela - which is either a very high bar or the beginning of a very funny joke."

There was no punch line.  The president did speak about the strong relationship between Britainand the United States and the challenges ahead. (read more here)

-On the British-American relationship: "But as we enter this new chapter in our shared history, profound challenges stretch before us.  In a world where the prosperity of all nations is now inextricably linked, a new era of cooperation is required to ensure the growth and stability of the global economy.  As new threats spread across borders and oceans, we must dismantle terrorist networks and stop the spread of nuclear weapons, confront climate change and combat famine and disease.  And as a revolution races through the streets of the Middle East and North Africa, the entire world has a stake in the aspirations of a generation that longs to determine its own destiny." 

-On Libya: "We will proceed with humility, and the knowledge that we cannot dictate every outcome abroad.  Ultimately, freedom must be won by the people themselves, not imposed from without.  But we can and must stand with those who so struggle.  Because we have always believed that the future of our children and grandchildren will be better if other people's children and grandchildren are more prosperous and more free - from the beaches of Normandy to the Balkans to Benghazi."

-On the "Arab spring": "History tells us that democracy is not easy.  It will be years before these revolutions reach their conclusion, and there will be difficult days along the way.  Power rarely gives up without a fight - particularly in places where there are divisions of tribe and divisions of sect.  We also know that populism can take dangerous turns - from the extremism of those who would use democracy to deny minority rights, to the nationalism that left so many scars on this continent in the 20th century."