Watch: Barack Obama's Speech at Nelson Mandela's Centenary Celebration

We collected some of the best social media posts about Barack Obama's first major speech since leaving the presidency.

Whether you're a fan of his legacy, or not, Barack Obama is one of the world's great living orators. Today, he is giving the keynote speech at South Africa's celebration of the late great Nelson Mandela's 100th birthday. Tune in above to see what Obama has to say about Mandela's legacy as well as the topics of the day like immigration, nationalism and economics.

Read our take on how people abuse Mandela's legacy here.

Understandably, social media is ablaze with commentary. See some of the best below:

Many people are blown away by Obama's on-stage charisma:

Barack Obama is like that ex that is liked by the family and still gets invited to family gatherings #MandelaLecture

— David Mqehlana ❁ (@Mqehlana) July 17, 2018

It could well be a reference to Trump but juxtaposing an Obama Presidency with African democratisation exposes how his government also supported the upkeep of dictatorial African regimes without pressuring reforms. The Deby's, Biya and Sisi's of this world to be exact https://t.co/6PYKaDIyWw

— Ryan Cummings (@Pol_Sec_Analyst) July 17, 2018

is someone going to ask Obama about Agowa? Libya? Black Living condition, mass killing and the high black incarceration rates in the US? So no one's going to ask him what the purpose of his Kenya trip was...no one? #MandelaLecture #MandelaObama

— Busisiwe C Seabe (@Ms_BSeabe) July 17, 2018

How do you speak about Mandela without mentioning Mam Winnie who waited for 27 years? South Africa why we hate Mam Winnie so much that every speaker doesn't recognize her work? #MandelaLecture

— Nkanyiso Ngqulunga (@Nkanyiso_ngqulu) July 17, 2018

When the guilty clap......👀#MandelaLecture

— robertmarawa (@robertmarawa) July 17, 2018

When Barack Obama said "So,young people,keep believing,keep marching,keep raising your voice."

#MandelaLecture pic.twitter.com/lzv8KTwZAe

— Lerato (@AndImLee) July 17, 2018

“Every generation has the opportunity to remake the world." #MandelaLecture

— Phiwah the boy (@PhiwahJnr) July 17, 2018