After all at his mother Princess Caroline's baptism in 1957, four bishops and 15 priests presided. The ceremony took place amid the splendour of the principality's cathedral, which had been filled with 10,000 lilies and tulips for the occasion.
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Such pomp and circumstance is unlikely to welcome her grandchild. The new parents are boho spirits who are happier soaking up the sun on a beach in Ibiza than holding court in the Grimaldi clan's stately 13th-century palace.
Their engagement announcement, a simple communiqué from Caroline's office, lacked even a mention of the pregnancy. Moreover Tatiana, the granddaughter of Colombia's second richest man, resisted the temptation to be seen flashing a princess-worthy rock.
So how will the scion of the two high profile dynasties be raised?
Andrea, 28, and his 29-year-old bride probably won't settle in Monaco. Instead, the family base will be in Paris away from the media spotlight, with regular forays to Rio de Janeiro, the home of her mother Brazilian socialite Vera Rechulski.
Tats, as friends call her, dislikes being the centre of attention. She recently told a Spanish publication: "I don't like being photographed. That's why I always look pained."
Even in a public setting like Paris Fashion Week, Tatiana can't understand the stampede to get her picture. "I thank goodness there can't be any celebrities left," she once quipped.
To understand the couple's insistence on privacy you also need to go back to Andrea's childhod. His father, charismatic Italian businessman Stefano Casiraghi, died after a speed boat accident in 1990 when the royal was just six.
His widow was too grief-stricken to break the news to her son and his siblings Pierre and Charlotte. So the task fell to her father Rainier III who had lost his wife Princess Grace after similarly tragic accident eight years earlier.
Caroline retreated to a French farmhouse, three hours drive from Monaco in an effort to shield her children from the intense press attention. Later, Andrea was sent to boarding school in Fontainbleau, just outside the French capital, where he met Tatiana.
On their marriage later this year, the little one will become third-in-line to the throne, after his grandmother and father. As Caroline's brother, the head of state Prince Albert and his wife Charlene are yet to produce a legitimate heir Baby Casiraghi will guarantee the succession.
So some family customs may be observed. Their baby may well wear the Valenciennes lace-trimmed christening gown once worn by great-grandfather Rainier.
The godparents will probably be drawn from the gypsy jet set the duo got to know as students. These include Greek shipping heiress Eugenie Niarchos (pictured back centre) and Margherita Missoni (front centre) of the Italian fashion family.
Favourite for godmother is Tatiana's chief confidante, her future sister-in-law; Charlotte (left) is also based in Paris.
Leading the candidates for godfather is her brother Julio Santo Domingo III, a DJ. They share a love of art and culture inherited from their dad Julio II who died in 2009 and was known for his large collection of manuscripts and rock 'n' roll.
Also a possibility are the two half-brothers of her late father.
Alejandro heads the $6 billion Santo Domingo empire. Meanwhile, Andres, a music exec, is one half of New York's most glamorous young couples along with his wife Lauren (pictured below). A protégé of Anna Wintour, she is the owner of online fashion portal Moda Operandi.
Despite these well-heeled connections, Tatiana rejects the heiress tag. A graduate in history of art, she has channelled her good taste into business.
She runs Muzungu Sisters, an ethical fashion line, which helps artisans in the developing world sell their handicrafts for a fair price. The work ethic she learned from her billionaire grandfather.
Speaking about her background, she said: "Everyone loves to invent fairytales about little princesses who can do whatever they want.
"(In reality) there are privileged people who still fight for what they believe in and try to build something rather than throwing away the money their parents left them."