When Ed Sheeran wrapped up the last date of his record-breaking Divide Tour in 2019, he thought his career might be over.

"I thought that was it," he told GQ earlier this year. "That was the top of the mountain and, you know, I'd never do that again. I thought it would be all downhill from here. The end of that tour hit me very hard."

He settled down to married life in Suffolk, took up painting, and became the proud father of a baby girl, Lyra, in the middle of the pandemic.

For months, the singer - one of the biggest-selling artists in the world - didn't even pick up a guitar.

"I was like, 'That's it, this is me, I'm just going to be a dad, I'm not going to play music anymore,'" he told Sirius XM radio.

And then, an epiphany.

"I was suddenly like, 'It is more important for my daughter to grow up knowing that her parents have work ethic and her parents love working hard and love creating and enjoy their jobs'," he said. "And seeing that rather than, like, looking at your dad as technically unemployed."

So here we are, with Ed Sheeran's fourth solo album, called = (Equals). It arrives in the busiest period for new albums in years - a week before Abba's unexpected return, two weeks before Taylor Swift's updated version of Red, and three weeks before Adele's "divorce album", 30.

Sheeran has a head-start over the competition, though. The first two singles from = (Bad Habits and Shivers) spent a combined 15 weeks at number one over the summer - proving, if nothing else, that the star had lost none of his knack for writing slick, memorable pop hooks.

The rest of the album is similarly polished, balancing Sheeran's ruthless commercial instincts with more introspective, emotional moments.

In keeping with the title, the 30-year-old's lyrical preoccupation is finding equilibrium in his personal life. The first words he sings are: "I have grown up/ I am a father now/ Everything has changed/ But I am still the same somehow."

Domestic bliss is never far from the surface, and the majority of the 14 songs are addressed to his wife, Cherry Seaborn, who he first met at school.

"The greatest thing that I have achieved/ Is four little words down on one knee," he recalls on First Times, the first of many tender ballads about their relationship. "You said, 'Darling are you joking?'/ And I just said, 'Please."

You get the feeling Seaborn might blush at some of his more effusive proclamations of love. "I never kissed a mouth that tastes like yours," he declares artlessly on Shivers. Worse still, he reminisces about "fumbling in cubicles in Tokyo" and "making love in the sky," on the mid-tempo TMI anthem, Collide.

He hits the target better on The Joker And The Queen, an utterly gorgeous cri d'amour, in which Sheeran sings in tones of hushed wonder about Seaborn's decision to slum it with him when she could have had her choice of "a thousand kings".

Brushed with layers of gauzy strings, it's bound to become a wedding fixture along the lines of the star's earlier hits, Thinking Out Loud and Perfect.

Elsewhere, he apologises to the family for the inevitable months he'll spend on tour (Leave Your Life) and plans a candlelit getaway (Love In Slow Motion).

The touching, folksy Leaving Hours is a tribute to his late friend and mentor Michael Gudinski which, unexpectedly, features Kylie Minogue and Jimmy Carr on backing vocals.

Future stadium anthem Overpass Grafitti combines the stormy synth-pop of The Weeknd with a chorus that invokes Don Henley's Boys Of Summer. It's another surefire number one.

Sheeran comes unstuck, though, on Sandman - a suffocatingly insipid lullaby for his daughter, coddled up in plinky plonky music box clichés.

It feels harsh to criticise a song with such a heartfelt sentiment - but it's been done better so many times before, from the unbridled joy of Stevie Wonder's Isn't She Lovely, to the fantastical whimsy of Madonna's Dear Jessie (and that wasn't even written about her own child).

But, in the end, that's what makes Ed Sheeran Ed Sheeran. The naivety of the lyrics can't undermine his credibility, because he never claimed to be cool in the first place.

That allows him to get away with schmaltzy declarations of undying love that'll be cherished by fans for the simplicity of the universal emotions they express.

All of which makes Sheeran impervious to crotchety music critics (including his own daughter). So while I could mention this album's lack of musical innovation, or the risk-averse, apolitical lyrics, what would be the point?

When it comes down to it, = is better, more coherent and less irritating than Sheeran's last proper album, 2017's ÷.

The no-nonsense melodies and burnished beats ooze self-assurance and Sheeran expertly balances the equation between his pop instincts and a new, more mature style.

It's a good thing he didn't give up, after all.

Not content with taking over the charts for the whole summer, Sheeran is hoping to score his second Christmas number one this year.

Speaking to Dutch radio station NPO Radio 2 earlier this month, he let slip that the track would be a duet with Sir Elton John.

"Elton rang me on Christmas Day to say Merry Christmas," Sheeran said. "He said, 'Step Into Christmas is number six in the charts! I want to do another Christmas song - will you do it with me?"

"He let the cat out of the bag didn't he?" Sir Elton later told the NME. "I was sworn to secrecy and then big mouth Sheeran goes to the Netherlands! We haven't finished it yet, so there's still work to be done."

Appearing on BBC Radio 2's Breakfast show on Friday, Sheeran let the cat even further out of the bag. In fact, he opened the back door and let it run into the garden, then turned a honking great spotlight on it.

Egged on by Zoe Ball, he played a world exclusive snippet of the track on an acoustic guitar from his home - where he's self-isolating after being diagnosed with Covid-19.

"It's the first time that much has been heard," he said, "II's definitely got loads of sleigh bells on it and will sound a lot more Christmassy than that, but that is a tiny hint of the song."

All of Ed's solo albums have been named after mathematical symbols - starting with 2011's + (Plus).

That album "added" new songs to classics from his early EPs and independent releases, including his breakthrough hit, You Need Me, I Don't Need You.

2014's x "was called multiply because it made everything that was on plus bigger," Sheeran told Entertainment Weekly in 2015. "From the venues to the songs to the radio plays to the sales."

Next in the sequence was 2017's ÷ (Divide) which saw the star partition his music into multiple genres, from the pop euphoria of Shape Of You to the more introspective Castle On The Hill. The album also divided critics, with the faux-Irish lilt of Galway Girl coming in for particular scorn.

Stuff magazine's Alan Perrot was particularly scathing, calling the song "cultural theft" that "appropriated an entire Irish folk tradition" while indulging in "a grab bag of Irish stereotypes that stops a 'to be sure' short of 'diddly-dee potatoes'".

Sheeran had the last laugh, of course. Galway Girl went platinum in 13 countries and ÷ ended up as the best-selling album of 2017.

Logic dictated that the fourth album in the sequence should be called - (subtract) and Sheeran previously hinted that it would be a more stripped-back release. "My idea for subtract was to not have anything on it, just be an acoustic record," he told EW in that same interview.

Instead, he's gone for = (Equals), an album that balance his pop instincts with a more mature sound, while talking about the harmony in his home life since becoming a father.