"I wrote without thought of what the songs would be, I just wrote whatever tumbled out. And in just over a week, I replaced a decade's worth of work with my deepest, darkest thoughts.

"For the first time I'm not trying to craft an album people will like, I'm merely putting something out that's honest and true to where I am in my adult life.

"It's opening the trapdoor into my soul."

The album is due for release on 5 May, and follows the one-off single F64, which was a visceral response to Jamal Edward's death.

That song will not feature on the final tracklist, which was revealed on Wednesday morning.

Sheeran's mathematical quintology has made him one of Britain's biggest music stars, with songs like Shape Of You and Thinking Out Loud among the most-streamed songs of all time.

Subtract, which was originally planned as an acoustic album, will now range from "paired back, folk-leaning textures to bolder, full-band/orchestral arrangements," according to a press release from Sheeran's record label, Atlantic.

Unlike his previous albums, the artwork for Subtract does not focus on the title's mathematical symbol, instead featuring a picture of a corroding heart.

The star also posted a cryptic video on Instagram, featuring his song titles scored into the shore of a windswept beach, intercut with footage of what appears to be a child's birthday party.