Prince Rainier, Europe's longest-reigning monarch, has died at the age of 81.
The prince, who had ruled Monaco since 1949, had been suffering from heart, kidney and lung problems. He will be succeeded by his 47-year-old son, Prince Albert.
Aware of his country's lack of natural resources, Rainier used his contacts and business skills to modernise Monaco's economy, developing light industry.
He also turned Monaco into a tourist resort tax-haven for the wealthy and a fashionable centre for business conventions. In 1956 he married the US Hollywood star Grace Kelly.
Send us your tributes to Prince Rainier.
This debate is now closed. Read a selection of your comments below.
My deepest condolences to the family of Prince Rainier, what has already been sad week has just become sadder with the loss of another great man.
Yvonne Toporowski, Canada
The tributes so far have missed one of the most significant contributions of Prince Rainier to the humanity. He has followed his family tradition of involvement with the natural history of the world seas by being the main sponsor of Jacques Yves Cousteau throughout most of Cousteau's career. We owe a lot of what we known now about the sea and the creatures in it to his generosity. It is amazing how much has a little country like Monaco contributed to our knowledge about the world and the environment.
Anton Ivanov, Cambridge, UK
Prince Rainier was a fine example as a husband to Princess Grace and to his children. What was most commendable, was that he did not re-marry after the death of his wife. He loved her! Prince Rainier will be sadly missed. My deepest condolences to his beloved family and grandchildren and to the people of his country.
Teresa R. Field, Henderson,Nv. USA
I'm very sad that Prince Rainier has passed away. God Bless him and his family. It's a really sad moment. My condolences to the family. Rainier, you'll always be in our hearts, thanks for your legacy.
This is the end of an era and a great loss for Monaco. I will remember Prince Rainier as a dedicated and dignified ruler. My heart and prayers go to his children and the Monegasques.
Beate, St. Albert, Canada
Recently I lost my natural father and now in the last few days following the death of his Holiness, the Pope, and Prince Rainier, I feel the world is a poorer place without three, kind, true and gentle men, Rest in Peace,
Stuart Goldsmith, Sutton Coldfield, England, UK
HSH Prince Rainier III lived a remarkable life. He was a great statesman, and man, whom Monaco was extremely proud of. He was an adoring husband, father and grandfather. He made Monaco what it is today. His great efforts and hard work throughout the principality will be a constant reminder to all that, while he is gone he will never be forgotten.
Elizabeth, Houston, Texas USA
My husband and I, and our 4 children lived in the Emilie Palace, on Avenue Princesse Grace in Monte Carlo, Monaco. My children had the honour of meeting Prince Rainier when he came to visit their class at the American International School in Fontveille, Monaco. He was kind enough to give each of the children a small stamp collection of Monaco stamps, which we still cherish. The nearly 5 years we lived there were some of the happiest and most fun years of our lives. Prince Rainier will always be fondly remembered, along with the rest of the Grimaldi family. Our thoughts and prayers are with you all at this time.
Diane Moore, Scottsdale, Arizona, USA
As I drove into work in Monaco this morning, every shop, office and house had a flag outside. The policemen are wearing black gloves and the flag at the castle on the Rock is at half mast. Today we are mourning our beloved Prince.
His Serene Highness Prince Rainier was the heart and soul of Monaco. He will be recognised as one of the most sincere and caring leaders of our time. My deepest condolences to Prince Albert, Princess Caroline and Princess Stephanie.
Pierre Bisset, Paris, France
Farewell Prince Rainier! I will never forget you for everything you did for Monaco. Thank you for saving our country from French attempts to regain control. May you rest in peace. Long live Prince Albert!!
Harold Garcia, Monaco
I send my condolences to Prince Rainier's family. I was once lucky enough to meet Caroline in Philadelphia and I send my prayers to her and her siblings.
Faith Morlan, Aurora, Col, USA
God bless you all, He will be greatly missed. America remembers, and mourns with you.
Ms Pat Worthey, Placerville, Ca, USA
I want to let the people of Monaco know had sad I feel, about the passing of Prince Rainier. He led a good life, and did a lot for the people of Monaco. He will be missed, and may his spirits live on forever. Take care Prince Rainier in the spirit world. Hope to see you there some day.
Roger E, Mt. USA.
The last chapter of fairytale is closed, but there is always new to come. Once upon a time never ends. My deeply condolences to the Grimaldi family and people of Monaco.
God Bless You and your family Prince Rainier. Rest in peace.
Cas Nowak, USA
Prince Rainier will be sadly missed as one of the great thinkers and designers of our time
On this sad day we mourn the loss of a true Prince and a real Gentleman. I hope that he is now reunited with the love of his life his much adored Princess Grace. This couple had style and dignity, they were the true meaning of a Fairytale marriage" may they rest in peace...
Ilene Gillard, Canada
Rainier will be greatly missed. He loved his family and his people so much. I pray he is in eternal happiness in the arms of his beloved wife. My thoughts and prayers to the Grimaldi family during this sad time.
Ben , West Newbury, USA
Prince Rainier was loved by millions. He will be sorely missed by all. My sincerest condolences to his family and the residents of Monaco.
Carol Biss, Ormond Beach, Florida USA
I have long admired his quiet strength. I wish his family peace and wonderful memories.
Heather Mc, Seattle, WA, USA
He was a pure gentleman and never let anyone down.
Orla Jameson, Liverpool
My deepest sympathies go out to Prince Albert, Princess Caroline and family and Princess Stephanie and family on the loss of their beloved Dad and Grandfather.
Nancy Y., Ohio/USA
The world will be a sadder place without this wonderful man.
Linda, Texas, USA
What a lovely man. Prince Rainer and his lovely wife made the ideal couple. He adored his princess and didn't get over her sad death. May his lovely wife be waiting for him.
M Grant, Aberdeen
To His Royal Higness Prince Albert and HRH Princesses Carolina and Stefany my deeply sorry for the death of Prince Rainier.
Manuel Palhares, Odivelas Portugal Europa
I must say that even though I have never heard of Monaco in my life, this man was obviously someone who took his duties seriously and used his position to the advantage of others, just like the late Pope. By marrying Grace Kelly, he put Monaco on the map. It was almost the greatest public relations exercise that he could have done. I have no doubt that he will be sorely missed.
Catherine, Suffolk, UK
May he rest in peace with his beautiful wife, Princess Grace.
A true, great, inspirational leader will be missed by all. Our thoughts are with the Grimaldi family who have lost a jewel ...
He has been through the thick and thin and endured the love of his people. But now, at least, he will be watching over us with his wonderful wife.
Eden Richardson, Ashby, Massachuesetts
The final page of a fairytale. A new chapter to begin. To the family of Prince Rainier and the people of Monaco my deepest sympathies. A true Prince among men.
G. J. Butt, Corner Brook, Newfoundland, Canada
My thoughts and prayers go out to the Royal Family and the people of Monaco on the passing of Prince Rainer. May it comfort them to know that he is now re-united with his beautiful wife and beloved Princess
Karen Burwash, Winnipeg, Manitoba
Another great leader and father is leaving us this year. I know that his son Prince Albert will continue his father's path. May he rest in peace,
Rick, Waterbury, USA
I am deeply saddened by the death of Prince Rainier, an exemplary father, husband and leader. I pray that Prince Albert, Princess Caroline and Stephanie find the strength to go forward and continue their parents' exemplary work and care for humanity. God bless them and their families.
Aimee Tersy, NYC, USA
Prince Rainier was a decent and wonderful leader, and Monaco will not be the same without him. You are now with your lovely wife Grace again. RIP.
Seven years ago I moved to Monaco to work for a year. The people of Monte-Carlo were extremely proud of, dedicated to and loyal to Prince Rainier. He was held in the highest regard, and respected more than any other ruler of any other country. Unlike other members of royalty, his loyal subjects had not a bad word to say about him. They loved and honoured him and will continue to even now.
Jan, Toronto, Canada
Words cannot express the loss of another huge figure in history. May he rest in peace with his beautiful wife.
GG, Vancouver USA
I always respected Prince Rainier and the principality of Monaco; a true old style royal has sadly passed away. He will be missed by many around world.
Abdul, Toronto, Canada
True humanitarian, full of dignity and much respected. Alas, we will sorely miss true class which the world has thrown by the wayside. Rest in peace, and kiss your Grace.
Melanie Archer, USA,
I am terribly sorry for the family and the people of Monaco, and the world, to lose such a wonderful man. And I think it is sad that his death has to be shadowed by the death of another wonderful man, the Pope. Prince Rainier was a glorious man and should never be forgotten.
Sarah Wright, Woodland California, USA
A lasting memory of my youth is Prince Rainier marrying Grace Kelly, a fairytale come true. So sad it ended but now maybe it will go on forever. Rest in peace.
Lynda Foster, Newport, England
God Bless You and your family Prince Rainier - the world will miss you greatly.
Josie, Toronto, Canada
To the entire Royal Family, my deepest sympathy and regards to you all during this time of sorrow. My prayers and best wishes for you. May God Bless you in the upcoming months and carry you all through a difficult time with the grace and respect you all deserve and have shown through the years. Deepest Regards.
Shea Elizabeth Cavacini, Griswold, USA
We mourn the loss of a great and dignified man today and our thoughts are with the Grimaldi family in their time of sadness.
My heart goes out to you, the family, and may God be with you at this time, and guide you through this time of need and grief. With Deep Prayers.
Mary Rose Hale, Hempstead, TX, USA
Prince Rainier will be sadly missed by all. He can now rest in peace. Good luck to Prince Albert.
Mary Johnson, Los Angeles, California
My heart is with his family, may Prince Albert's reign be has long and successful as his father.
Kristina, age 14, Weston-super-Mare, UK
At last he is reunited with his beautiful wife Grace. He has looked a lonely figure since her untimely death and I hope they rest in peace together.
Kay Austin, Durham, UK
My mind today is not only on Prince Rainier, but also on Aristotle Onassis who brought the Prince and Grace Kelly together.
George Bonanos , Athens, Greece
A fine man, a fine country and wonderful people. Having worked in Monaco last year I got to know how the people loved this man, the whole area draped in red and white flags for his birthday last year. I hope Prince Albert takes to the role and continues as his father before him. RIP Prince Rainier.
R Charlesworth, Germany
To have created such a place from nothing takes courage and vision. To have fought off challenges from such as de Gaulle, to have fought in combat in the last war, to have offered a steadfast and keen interest for years in motorsport in general, not just Formula One, to have shown dignity at all times. What more can be asked of any prince?
Jon Champs, Northampton, UK
Hope Prince Rainier is now at peace and reunited with his beloved wife. I will always remember whilst stood alone in the Palace grounds after the grand prix that, as his car passed, he smiled and waved. He seemed happy being with his family around him, and my prayers are with them and the people in Monaco.
Miss Debbie Chaplin, Ipswich, Suffolk, England
Many years ago I read a book called Rainier and Grace. I wrote to the prince and he replied with a lovely letter. I have been lucky enough to visit Monaco and the beautiful palace. He seemed a lovely man and I'm sure he will be missed by all his subjects but happy now he is reunited with his beautiful wife.
Morag Clarke, Leicester, England
A sad week has just become worse. Rest in peace, Prince Rainier.
Jasimin, Toronto, Canada
A true royal - more dignity than our royals I believe!
Janis, Newbury, Berkshire, England
I loved him with all my heart. I have never seen a ruler of this magnitude. His like will never be seen again, it is the end of an era. God rest his soul. He was a good man.
Uche Opara, London, UK
One of the greatest men in the history of European monarchy. He helped introduce the principality into the modern world. He will no doubt be missed by both the people of Monaco to whom he was their prince, and the people of Europe.
Ryan Downs, Londonderry Northern Ireland
May he rest in peace. He had a life showing him as a gentleman prince. He always showed a personal dignity. His family personal life he knew how to dissipate very hurtful moments caused by his female descendants.
Arnaldo Ortiz, Mexico
My sympathy to the Rainier Family - you have lost a prince of princes- a man the world looked up to. My prayers are with you.
A Raio, Maplewood, NJ, USA
Prince Rainier was a good man. His family, we are sure, are proud of him. A person who gave and did so much, who had lost something so dear to him so early in his life - Princess Grace! He had never forgotten her. At last he has gone to join her. May you rest in Peace, Prince Rainier and God Bless you.
Desiree, Cape Town, South Africa
Don't know much about Prince Rainier, having actually heard more about his children, but he seemed to have led his country with dignity and class. I am certain he will be missed.
Jill, Atlanta, USA
To the royal family and the people of Monaco, my sincere condolences. May God Almighty grant you strength.
Syed Mohazri Al_Qadry, Malaysia
Sincere sympathy for the happy repose of his soul.
He was very regal. I hope that Albert and Charles and the rest of the next generation will shape up and follow his example.
Peter, La Marque, Texas
Prince Rainier was truly a good and honourable man who will be very much missed. My prayers go to God for the repose of his soul. May his son, Prince Albert, attain the good reputation his father and mother had and may he rule Monaco well and set a good example to his people. God bless you Prince Rainier.
Antonio Perez, San Diego, California U.S.A.
I think that the prince has been outstanding in his life and has been a big influence on my life, He will be sadly missed by all royalty throughout the World.
Richard Pepper, Reading, UK
May he rest in peace. I met the family and Princess Grace when I was 11 years old. They both shook my hand at a ceremony dedicating a rose garden to Francis Meilland. It was a marked moment for me. I've always felt a closeness to the Monegasque monarchy since then and especially since the untimely death of Prince Rainier's most elegant wife, Grace. He was a real monarch. His son, not much older than myself now, is a fine tribute to the continuing monarchy. God rest his soul.
Tony Carey, Edgewater, MD
Prince Rainier is proof that sometimes monarchy does work, if the monarch exemplifies dignity and love for his country, as he did. May he rest in peace, along with his one and only love, Princess Grace.
Billy, Toronto, Canada
He turned a tiny mediaeval principality into a modern nation, and transformed the name Monaco from one associated with triviality into one associated with the movers and shakers of the business world.
Donald, Niagara Falls, NY, USA
Prince Rainier really won the hearts and minds of his people. He was also able to recognise the challenges and chances brought by time and turned his princedom into a fruitful business centre. His life was a far cry from the scandals of his children that had afflicted the Royal Family of Monaco. May his soul rest in peace.
Mary McCannon, Budapest, Hungary
An example to many, a monarch who modernised his country, remained strong even on the untimely death of his late wife. Maintained his dignity. Although this is a very sad day for his countrymen, they can be proud of a world figure and leader.
Paul Thomas, Cyprus
I am most impressed that this man gave up most of his Royal titles and privileges to further his country's prosperity. I do hope that Prince Albert, like his father once did, finally settles down at the not-so-spring-chicken age of 47 and produces an heir.
Jim, Los Angeles, CA