Cary Grant and Grace Kelly starred together in only one movie, Alfred Hitchcock's "To Catch a Thief" (1955). Grant loved working with Grace and would state many years later that she was his favourite leading lady of all time ("Well, with all due respect to dear Ingrid Bergman, I much preferred Grace. She had serenity.") But it was not only on the set he got along with Grace, the two stars also enjoyed each other's company outside of work. After Grace had become Princess of Monaco in 1956, they kept in touch and Grant would make occasional visits to Monaco.
On 26 February 1966, Cary Grant became a father for the first and only time (he was 62 years old). With his fourth wife Dyan Cannon, to whom he was married from 1965 till 1968, he had a daughter named Jennifer. Two days after she was born, Grant received a telegram from his friend Grace congratulating him on becoming a father:
(..) FEB 28 66 (..)
(..) MONTECARLO (..)
MR CARY GRANT
242 NORTH CANNON DR BEVERLY HILLS (CALIF)
THRILLED AND DELIGHTED OVER WONDERFUL NEWS RAINIER JOINS ME IN SENDING CONGRATULATIONS AND BEST WISHES LOVE