The partnership behind some of the best-loved characters in children’s literature is being celebrated at a free interactive exhibition.

For several generations of young children, they have been constant companions, taking them on exciting adventures and introducing colourful characters.

For parents, their work has provided many a bedtime solution; a shared experience that will remain a treasured memory long after their child has grown up.

Now the work of best-selling children’s author Julia Donaldson and illustrator Axel Scheffler is being celebrated in an exhibition at The Lowry, Salford Quays, marking the pair’s remarkable 30-year partnership.

Great British Life: The Gruffalo, Julia Donaldson and Axel Scheffler's most famous character, created in 1999. (c) Macmillan Children's BooksThe Gruffalo, Julia Donaldson and Axel Scheffler's most famous character, created in 1999. (c) Macmillan Children's Books

Since collaborating on their first book – A Squash and a Squeeze in 1993 – the duo have become the undisputed champions of children’s literature, responsible for major bestsellers including The Gruffalo, Room on the Broom, Stick Man, Zog and The Smeds and The Smoos.

On a flying visit to The Lowry to see where Julia and Axel – Thirty Years of Favourite Stories is to be staged, the pair appear genuinely humbled by the popularity of their work.

'We have been incredibly lucky,' says Axel. 'It is amazing and you do have to pinch yourself at times. It is so touching when you meet the readers and hear how much the books means to them.'

Julia says: 'I just feel very fortunate to be doing this. To hear from parents who are so grateful for the books and say that they have given them and their children hours of pleasure – what a great thing to have achieved in life.

'It’s so gratifying to think your work has spanned the generations and that the parents who first read the books to their children are now the grandparents and the children are now the parents reading the same books to their children. You just hope that that can go on and on.'

The Julia and Axel exhibition is the first time so many of Julia's personal notebooks have gone on display to the public, giving visitors the chance to see her original ideas for characters and some of the rhymes that didn’t make the final edit. Axel has loaned more than 100 of his original drawings and sketches, showing how he develops characters having been sent Julia’s finished manuscript for a book.

Great British Life: A Squash and a Squeeze from Julia Donaldson and Axel Scheffler. (c) Macmillan Children's BooksA Squash and a Squeeze from Julia Donaldson and Axel Scheffler. (c) Macmillan Children's Books

'I never know what the next book is about so it is a big moment when the publisher sends me the manuscript. I quite like that,' he says. 'But it’s a very professional process and we have done so many books together now.'

Julia reveals: 'I don’t give anyone a clue as to what the book I’m working on is about, not even the publishers. If I said I was going to write a story about a ghost, for example, and the publishers said something like, "well, don’t make it too scary," that would stop me being able to write it. I need to have complete faith in myself and the book so I will always complete it before letting anyone see it.'

Axel is not the only illustrator Julia works with and her output is prolific – she’s written in excess of 200 works for children in her career. He also works with other authors but the pair have so far collaborated on more than 25 books.

'There are certain books where I have Axel completely in mind from the outset,' she said. 'I trust him completely and never worry at all what he might come up with.'

Julia, 74, is passionate, artistic, shrewd and a natural performer. She prefers to be described as a performer rather than a writer and one of her greatest delights is to read her books to captivated audiences of youngsters with many a book signing turning into a full-blown performance

Before her publishing career took off she was a songwriter and singer. She met her husband of 50 years, Malcolm, when she was part of a group performing during Rag Week at Bristol University while studying drama and French.

Great British Life: Charlie Cook's Favourite Book, cooked up by Julia Donaldson and Axel Scheffler. (c) Macmillan Children's BooksCharlie Cook's Favourite Book, cooked up by Julia Donaldson and Axel Scheffler. (c) Macmillan Children's Books

Born in German, Axel, 65, came over to the UK in 1982 to study at the Bath Academy of Art and it was there he realised his talents lay as an illustrator. He had been working as a freelance when a publisher introduced him to Julia for A Squash and a Squeeze and their partnership – dubbed ‘the Lennon and McCartney of children’s literature’ – was formed.

'He still surprises me all the time,' says Julia. 'I know the style and how the characters will look but it’s all the little extra details he adds. He always puts these little details into his illustrations I know children love to discover as much as I do.'

In spite of their amazing continued success – Julia was the best selling author in the UK across all genres in 2022; Axel the best-selling illustrator and The Baddies, their most recent collaboration, the UK’s best-selling picture book of 2022 – neither takes anything for granted.

'There is a pressure,” says Julia. 'You do feel people are expecting great things with every book. It’s rather like being a concert pianist; your last performance is always going to be what you are judged on.'

You sense that for all their success – The Gruffalo alone is available in 107 languages and dialects – the Lowry's Julia and Axel exhibition is something they are particularly proud of.

Great British Life: Julia Donaldson and Axel Scheffler, whose 30 years of bringing joy to young booklovers is being celebrated at The Lowry. (c) Phil TragenJulia Donaldson and Axel Scheffler, whose 30 years of bringing joy to young booklovers is being celebrated at The Lowry. (c) Phil Tragen

'I do like the title, that they are just using our Christian names,' says Julia. 'That was actually my idea,' she adds with a grin. 'But what I particularly like is that the exhibition is free. That’s marvellous.

'So often parents have to fork out for things to treat their family but this costs nothing.

'It is exciting to be able to share some behind-the-scenes secrets with our young readers and to show what happens before a finished book is in their hands. I hope it will help them to feel creative and to start writing and illustrating their own stories, so we have new picture-book creators in the future.'

Michael Simpson, the Lowry’s director of visual arts, and the man responsible for bringing the Julia and Axel exhibition to Salford, says: 'We are over the moon to have this exhibition at The Lowry.

'For any writer to hand over their notebooks or any artist to hand over their first sketches is a huge thing to do.

'We are proud that they feel that they can trust us to look after them and to show them the way they want them to be shown.

'Our aim is to have an exhibition that loads of young people and their families will come to and have a good time at.'

Great British Life: The wonderful array of characters conjured up by Julia Donaldson and Axel Scheffler. (c) Macmillan Children's BooksThe wonderful array of characters conjured up by Julia Donaldson and Axel Scheffler. (c) Macmillan Children's Books

Julia and Axel follows on from the Picture This exhibition last summer, which featured six popular children’s books by different authors, including Room on the Broom by Julia and Axel.

'That really struck a chord with families,' says Michael,' so when we realised this year was the 30th anniversary of Julia and Axel’s partnership, we asked if an exhibition would be possible and the publishers said yes.

'And we are absolutely delighted at the massive personal commitment both Julia and Axel have made to it, both in giving their time and advice and also in lending us so many precious items from their personal archives, many of which have never been seen before.'

Great British Life: Michael Simpson, the Lowry's Lowry’s director of visual arts, who has brought the Julia and Axel exhibition to Salford. (c) Nathan CoeMichael Simpson, the Lowry's Lowry’s director of visual arts, who has brought the Julia and Axel exhibition to Salford. (c) Nathan Coe

As well as the show of artwork and notebooks, a whole range of activities form part of the six-month-long exhibition.

'We want to help inspire the next generation of Julias and Axels,' says Michael. 'So we are going to make sure there are loads of opportunities in the exhibition to write, draw, read and to make things and to come up with your own stories. We want it to be an opportunity for children to think "I can do that, I’m going to give it a go".'

Julia and Axel – Thirty Years of Favourite Stories is at The Lowry, Salford Quays from runs until January 1 2024. Admission is free. Details from thelowry.com