Britain's Duchess of Sussex will publish a children's book next month titled The Bench.
It is about the relationship between a father and son based on her husband Prince Harry and the couple's child Archie, the publisher said.
The book is the latest venture by Meghan Markle and Harry, Queen Elizabeth's grandson, since they stepped down from royal duties and moved to Los Angeles in the US last year with Archie, who celebrates his second birthday later this week.
Illustrated by artist Christian Robinson, The Bench will be published on June 8, with Meghan narrating an audiobook version, publisher Random House Children's Books said.
"The Bench started as a poem I wrote for my husband on Father's Day, the month after Archie was born. That poem became this story," the duchess said.
"My hope is that The Bench resonates with every family, no matter the make up, as much as it does with mine."
Meghan, who is pregnant with the couple's second child, is not the first royal to venture into the world of children's literature.
Prince Charles, Harry's father and heir to the British throne, wrote The Old Man of Lochnagar, based on stories he used to tell his young brothers.
Sarah Ferguson, the Duchess of York, has also penned a number of children's stories.
Meghan and Harry have rarely been out of the media spotlight since they gave an explosive interview to US chat show host Oprah Winfrey in February, accusing one unnamed royal of making a racist remark and saying Meghan's pleas for help when she felt suicidal were ignored.
Harry returned to Britain for the first time since that interview for the funeral of his grandfather Prince Philip last month.