Duke of Cambridge's speech is thought to be part of plans, backed by Downing Street, to persuade Scotland to resist a vote on Scottish independence.
Prince William spoke of his deep connection with Scotland, while addressing the General Assembly of the Church of Scotland on Saturday.
His speech came at a sensitive time as calls for a referendum Scottish independence grow.
Analysts say the Duke of Cambridge's comments are part of plans, backed by Downing Street, to persuade Scotland to resist nationalist demands.
"Scotland is incredibly important to me and will always have a special place in my heart," said the Prince.
"I've been coming to Scotland since I was a small boy. As I grew up I saw how my grandmother relishes every minute she spends here and my father is never happier than in walking among the hills."
Prince William also explained how Scotland was associated with some of his deepest emotions,
"In short, Scotland is the source of some of my happiest memories but also my saddest. I was in Balmoral when I was told that my mother had died." He added: "It was here in Scotland 20 years ago this year that I first met Catherine (Duchess of Cambridge). Needless to say, the town where you meet your future wife holds a very special place in your heart."
Royal trips are usually planned long in advance so this week-long visit by the Duke and Duchess of Cambridge is being seen as part of a campaign known as "operation save the Union."
Meanwhile Nicola Sturgeon, Scotland's first minister and leader of the Scottish Nationalist Party, says a second independence referendum is “a matter of when, not if," after her party won its fourth straight parliamentary election earlier this month.
The British Prime Minister Boris Johnson is just as determined to block such a vote.