Taylor Swift was joined by "best friend" Ed Sheeran as she kicked off the final part of the European leg of the Eras Tour on Thursday evening at London's Wembley Stadium.

Performing a mix of the two songs they've made together, Everything Has Changed and End Game, Swift thanked Sheeran for appearing alongside her to perform to a sell-out crowd of 92,000 fans.

The concert was her first performance since the cancellation of shows in Vienna last week because of a terror threat.

It was also the first time she'd returned to the UK since an attack in Southport last month, in which three children were killed at a Swift-themed dance class.

The BBC understands that Taylor Swift has privately reached out to the families affected by the attacks.

She did not reference either event during the show.

Gigs in the Austrian capital were cancelled after authorities said they had foiled a terrorist plot, which was planned for one of Swift's sold-out shows at the Ernst Happel Stadium.

The 34-year-old, who has not spoken publicly about Vienna, did release a statement after the three little girls were killed in Southport.

She said she was "completely in shock" at the "loss of life and innocence".

As has been the case with most of the Eras Tour, things ran pretty much as expected.

But Sheeran's appearance during the surprise acoustic section of the evening prompted a huge roar from the 92,000 audience members.

The songs featured in the acoustic section towards the end of the show are kept secret from the audience until they are performed.

After a mash-up of their 2012 hit Everything Has Changed, the pair then launched into 2017 collaboration End Game.

Swift then repaid the favour by duetting on Sheeran's mega-ballad Thinking Out Loud.

"This is one of my best friends in the world," she told the crowd at the end of their mini-set.

"He works so hard, he's on tour right now and he's probably so tired but he wanted to come and play for you," she added.

With a runtime of more than three hours, there's not much time for rambling ad libs on the setlist and apart from this, Swift's interactions with the audience stayed on script.

Swift thanked the crowd throughout, and whilst introducing the Folklore and Evermore era of the evening, she told fans how overwhelming the crowd size felt.

She said she would miss performing to these crowds and was experiencing "feelings and emotions I didn't think about before talking about it".