When she was growing up in Ohio, Katie Holmes shared a fantasy with millions of other girls. “Every little girl dreams about her wedding,” she said. “I used to think I was going to marry Tom Cruise.”

Well, now she has, and a popular website can abandon its campaign to “liberate Katie, a young, gifted actress held captive by forces we may never understand”. It can also pack away its T-shirts, trucker hats, stickers and coffee mugs bearing the message “Free Katie”.

Yesterday’s “wedding of the year” in front of a star-studded congregation at Odescalchi Castle near Rome was another sort of liberation for the hazel-eyed actress after enduring sneers that her relationship with Cruise, 17 years her senior, was just a publicity stunt. They said her pregnancy was a pillow stuffed up her jumper; that Suri, the couple’s daughter born in April, was so badly disfigured she couldn’t be seen in public; that the wedding would never take place. Wrong, wrong, wrong.

For Cruise, the occasion underlined his sensational comeback from the wilderness after being dumped by Paramount three months ago, accused of “creative suicide” for his sofa-trampolining performance on The Oprah Winfrey Show and his zealous embrace of scientology. But once again the ever-grinning actor had the last laugh.

Restored to glory earlier this month as the new head of United Artists, yesterday Cruise had all the confirmation he needed that he remains Tinseltown’s most powerful honcho, as he surveyed a pantheon of A-list wedding guests, including John Travolta, Will Smith and Giorgio Armani, who designed the wedding dress.

As the couple exchanged vows before a scientology minister flown in from the States, Holmes might have pondered his words: “Know that life is stark and often somewhat grim.” In the sect’s typical wedding ceremony, she would also hear the question, “and when she’s older, do you keep her still?” It’s a sobering thought. Cruise’s amorous entanglements can be plotted along a steeply descending age curve. His first wife, Mimi Rogers, a voluptuous actress who sparked his interest in scientology, is now 50. Nicole Kidman, to whom he was married for 11 years, is 39 and Penelope Cruz, the Spanish beauty with whom he had a highly publicised dalliance, is 32. Holmes is 27.

Vows aside, Holmes can be in no doubt what Cruise expects from her. “She’s got to be pretty active because I travel all the time,” he said last year. “It’s also important that she can take instruction well. I’ll teach her how to fly a plane and ride a motorcycle.”

Hence, perhaps, the pre-wedding jitters she was reported to have confided to a visitor at a Colorado retreat where she stayed after the birth of her baby. She allegedly told him she was no longer sure about committing to Cruise, adding: “I don’t have my own life any more. I’m not comfortable.” According to the report, Cruise wanted her to stay at home and was keen for her to become pregnant again, while she pined to return to her career.

Career? Holmes seemed to have risen without trace when the public spotlight hit her at the top of the Eiffel Tower, where Cruise proposed to her in June last year. In fact she has 13 films to her credit, notably the recent Batman Begins, in which she played a childhood friend of Bruce Wayne who falls in love with his alter-ego, Batman, but cannot reconcile the two.

This tale of unrequited love mirrors her own experience. She briefly dated the actor Joshua Jackson before beginning a long relationship with Chris Klein, the star of the American Pie movies, who proposed with a £500,000 ring on Christmas Eve 2003. They planned to marry in Los Angeles. “When I was younger I had ideas of being a princess on my wedding day,” she sighed. Sounds familiar? Then along came Tom.

According to one version of how they met, Holmes went to ask Cruise for a part in Mission: Impossible III. Another version holds that “his people” summoned her and she ended up getting a flying lesson from Cruise above the city. The chemistry was instant. The age difference “never crossed my mind”, she said. Nor did the height difference — at 5ft 9in she is 2in taller than Cruise’s official height. They both had films to promote, and so the uncharitable murmurings began.

Cruise couldn’t hold back, proclaiming his love for Holmes to a startled Oprah with a courtship display that would not have disgraced a blue-footed booby. “I can’t be cool, I can’t be laid-back,” he declared, hopping into the air. “I can’t focus. I have never had this kind of feeling before. It’s something that has happened and I want to celebrate it.”

Holmes demonstrated that she, too, had mastered the coos and flutterings of this bizarre ritual when she gave an interview to W magazine in America in August 2005. “I’ve found the man of my dreams,” she said. “From the moment I met him it just felt like I’d known him forever. I was blown away. He’s the most incredible man. He’s so generous and kind, and he helps so many people and, um, he makes me laugh like I’ve never laughed.”