For Winston Churchill, it was an idyllic Mediterranean cruise on the most luxurious yacht in the world. But he and the other guests on board the Christina were aware of an atmosphere fraught with tension. 'It was the moment when I knew I'd joined the grown-ups,' recalls Churchill's granddaughter Celia Sandys, who, as a coolly observant 16-year-old, was awake to undercurrents of awkwardness at the dinner table.
She was witnessing the beginning of one of the great love affairs of the 20th century, between Aristotle Onassis and the diva Maria Callas, all played out in front of Ari's wife, Tina. By the end of that cruise, in the summer of 1959, the marriages of both Onassis and Callas would be over.
None of the women in the party liked Callas, and they were appalled when she coquettishly tried to feed the bemused, octogenarian Churchill with ice-cream from her own spoon. Celia, along with her mother, Diana, and grandmother, Clementine, Churchill's wife, bonded in their down-to-earth English dislike of this tiresome drama queen.
'There was a great sense of camaraderie between us once we realised this affair between Callas and Onassis had started. We'd exchange glances across the table and get together in my grandmother's cabin every evening to gossip about the day. It was rather fun. These were the sort of things I'd read about in the News Of The World - when I could get my hands on it,' Celia reminisces now, nearly 50 years on.
She also remembers with much amusement when Gracie Fields boarded the yacht at Capri. The diva made them all suffer a singsong of homely tunes around the piano.
Churchill was fond of Gracie but enough was enough. 'We love you, we do, Sir Winston, we luu-urve you,' warbled Gracie to the tune of Volare. 'God's teeth! How long is this going on?' Churchill muttered, in too loud a stage whisper, to his private secretary Anthony Montague Browne.
As for Callas, she completely failed to grasp that for once somebody else was centre of attention. 'She was terribly irritating,' laughs Celia, thinking back to a shore excursion to the Greek amphitheatre at Epidaurus, where locals had erected a huge floral Victory-V in honour of Churchill. Callas was first puzzled, then furious when she realised the flowers weren't for her. Later, without humour, she remarked, 'It's a pleasure to travel with Sir Winston. He removes from me some of the burden of my popularity.' For Celia, now 65 and a mother of four living in west London, it was always a pleasure to travel with her grandfather and in the last years of his life she spent several holidays with him in the penthouse of Monaco's famous Hotel de Paris. As he was wont to say, 'My tastes are simple. I am easily satisfied by the best.'
More recently, Celia has been following in her grandfather's footsteps for a Discovery Channel documentary series, Chasing Churchill, retracing his travels - military, political and private - from his early days as an ambitious young man desperate to make his mark until his final journey to where he was buried at Bladon, in Oxfordshire.
Celia found herself accompanying the most famous man in the world, not out of favouritism, but because 'I just happened to be an available grandchild of an appropriate age'.
And, to her, Churchill was first and foremost a dearly loved Grandpapa. 'He was a very warm person, no question of it being difficult or stuffy to be with him. I wasn't interested in politics at that age, so we'd be more likely to talk about whether his horse had won the latest race or where he'd painted that afternoon.'
Mindful of financial humiliations endured in his own youth, he would pull out wads of banknotes. 'He'd say, "How are you for money, darling?" I always thought it was his winnings from the casino!' remembers Celia, for there was a discreet underground passage linking the hotel to the nearby Monte Carlo gaming house.
'And, very definitely, he wanted to share his pleasures. If he was drinking champagne, he wanted everybody else to drink champagne. When I was about 15, there was an elderly cousin who complimented my mother on her daughter - that was me - and then went for the kill... "Pity the child drinks so much!"
'My mother said I didn't drink. "But she's always got a full glass of champagne," said the cousin. "You watch," said my mother. "She has a glass because it pleases her grandfather but she doesn't drink it... so it's always full." I didn't like champagne then, though I've made up for it since.'
Churchill, however, wasn't always such a welcome guest as he was on Aristotle Onassis's yacht and, to Celia's great amusement, researching her grandfather's travels led her to meet the American Senator Harry Byrd Jr, 'a lovely, lovely man', now well into his 90s, who has the oldest living memory of Sir Winston.
He was only 14 when he met the 54-year-old Churchill in 1929 through his father, who was governor of Virginia. But Churchill outstayed his welcome at the governor's mansion, at least in the opinion of the governor's harassed wife.
'My grandfather stayed for ten days and irritated Mrs Byrd by changing mealtimes and menus - and he'd also walk around upstairs in his underwear, and she didn't like that either,' Celia explains. 'Then there was a state dinner and the menu included Virginia ham. Churchill asked for mustard and the butler was sent to the kitchen, came back and said, "I'm sorry, but we don't have any mustard." And Mrs Byrd said, "If you like, I could send to the store." Never expecting him to say, in the middle of dinner, "Yes, that would be very nice."
'And so they all had to wait while the food got cold. When my grandfather left, Harry Byrd remembers his mother turning to his father, and saying, "Don't you ever ask that dreadful man here again!" as the car went out of the drive.
'There was another dinner in Virginia, probably the same visit, when the butler came around with the chicken and asked my grandfather which piece of the bird he would like. He said, "I'd like breast." Whereupon the woman next to him said, "Mr Churchill, in this country we say white meat or dark meat."
'Next day she got a corsage of flowers, saying, "Pin this on your white meat!"'
But while Churchill could often be a high-maintenance guest, on other occasions he could be disarmingly charming. Mary Jean Eisenhower, President Eisenhower's granddaughter, recalled that on a visit to the White House in 1959, her eight-year-old sister interrupted Churchill's conversation with the President to inform him that her doll's nappy had fallen off. Without batting an eyelid, or breaking off his talk, Sir Winston fixed the nappy. 'I was amazed,' Celia says, smiling. 'I can't imagine my grandfather would have known what a nappy was!'
Celia's satisfaction has been in uncovering affectionate stories about her grandfather that wouldn't even make a footnote in a history book. In South Africa, she made a television appeal for people whose parents' or grandparents' lives had touched upon that of the young Churchill in the Boer War. In the small town of Estcourt, at a drinks store called The Plough - Churchill's 'local' - met Derek Clegg, grandson of the local stationmaster whom he befriended in 1899, when, as war correspondent for the Morning Post, he was making daily excursions to spy on the Boers.
He recalled the story of how, night after night, Churchill would regale his fellow drinkers with tall tales of his previous soldiering adventures. 'He told a lot of stories and, of course, they all sounded unbelievable,' said Derek. ' Eventually, when everyone was laughing, he got fed up and said, belligerently, "Mark my words, one day I'll be Prime Minister of England."
And many years later, in 1940, when my grandfather had retired, Derek opened his newspaper and said, "By Jove, he's done it!"' The tale of how Churchill was ambushed and arrested by the Boers and staged his audacious escape from prison by hiding in a latrine and climbing over a wall has, of course, been told many times before. 'I know what happened,' says Celia. 'But what I wanted to know was what people thought about my grandfather at the time. One family produced a little note - written by him on the train journey from Natal to Pretoria as he was being taken into captivity. He was being guarded by a young soldier and they got into conversation. And, before they parted, my grandfather wrote on a tiny scrap of paper, "This man has treated me very well. If he is captured by the British, please treat him kindly."'
Churchill had several narrow escapes on his travels, even in peacetime; bullets whistled past his head more than once, and in New York in 1931 he was run over by a car on Fifth Avenue, protected only by his heavy overcoat.
'I do not understand why I was not broken like an eggshell or squashed like a gooseberry,' he wrote in the Daily Mail. 'I certainly must be very tough or very lucky or both.'
From early on, he'd had faith in his luck. 'Bullets are not worth considering,' he wrote to his mother from the dangerous North West Frontier of India in the 1890s. 'Besides I am so conceited I do not think the Gods would create so potent a being for so prosaic an ending.'
Had the gods been inclined to prove him wrong, World War II might have been very different. As prime minister of a beleaguered nation, he travelled constantly during the war - even adjusting happily to a bottle of red wine with his breakfast in North Africa, where he didn't care for tinned milk in his tea.
For all the pressures of war, there were occasional snatched moments. 'You cannot come all this way to North Africa without seeing Marrakech,' he insisted to the wheelchair-bound President Roosevelt after their Casablanca Conference in
1943. Determined to share the sunset over the Atlas mountains, he arranged for the President to be carried to the rooftop of their villa. Celia laughs. 'Roosevelt was reclining on a divan with silk cushions and he lifted his hand to my grandfather, and said, "I feel like a sultan... you may kiss my hand, my dear!" History doesn't relate my grandfather's response.'
Nearly 20 years later, when Celia was on holiday in Monte Carlo with her grandfather, then 87, one morning she found that he had fallen and broken his hip in the night. Sir Winston said he wanted to die in England and an RAF air ambulance flew him home.'I'll never forget the journey,' Celia says. 'I've never seen anybody look as vulnerable. We didn't talk, I just sat and held his hand - and there was a real chance that he wasn't going to make it.'
But as he was carried off the plane, Churchill rallied and gave the V-sign for Victory. He recovered sufficiently to take one more holiday with his granddaughter: 'But everything slowed down after that,' says Celia. 'What was nice for me was to have to myself the man the whole world thought they owned. Just for a little while, to have this companionable time.'
On the day of his state funeral in 1965, she travelled with her grandfather's coffin on his final journey as crowds lined the streets and even the building cranes along the Thames dipped their heads like great sorrowing birds.
'He was a lovely grandfather,' says Celia. 'He still casts a ray of summer on the family.'