• The story will be accompanied by images from the award-winning illustrator Christian Robinson.
• The duchess will also voice an audio version of her book.
The Duchess of Sussex is set to publish a children's book about father-son relationships, as seen through the eyes of mothers.
The Bench will be published on 8 June and is said to be inspired by the bond between her husband Prince Harry and their son Archie.
"The Bench started as a poem I wrote for my husband on Father's Day, the month after Archie was born," the duchess said in a statement.
"That poem became this story."
She added: "My hope is that The Bench resonates with every family, no matter the make-up, as much as it does with mine."
The story will be accompanied by images from the award-winning illustrator Christian Robinson.
The duchess will also voice an audio version of her book.
The publishers, Penguin Random House, said the book aimed to evoke "a deep sense of warmth, connection, and compassion".
It added: "It gives readers a window into shared and enduring moments between a diverse group of fathers and sons - moments of peace and reflection, trust and belief, discovery and learning, and lasting comfort."
The book is the latest in a number of ventures the Sussexes have taken up since their decision to step away from royal duties in 2020 to move to the US and pursue an independent life.
The couple have since launched their own charitable foundation, Archewell, and the duchess voiced the Disney nature film, Elephant. Archewell inspired them to begin a podcast of the same name in which they aim to foster wellbeing and kindness.
They have also secured commercial contracts thought to be worth millions, including a Netflix deal to produce TV projects and a Spotify deal for podcasts.
Their first project for Netflix will focus on the Invictus Games, a competition for injured military personnel and veterans that was championed by the prince.
He also recently announced he was joining mental health and life coaching start-up BetterUp as a "chief impact officer".
The duchess's book is not her first venture into writing.
She used to write a lifestyle blog called The Tig - which shut down after she began her relationship with Prince Harry.
Archie turns two on Thursday and the couple are expecting their second child, a girl, later this year.