VIPs whizzed by speed boat through Venice on Thursday as the three-day wedding party of Amazon tycoon Jeff Bezos and Lauren Sanchez kicked off and protesters demonstrated in St Mark's Square.
US reality TV personalities Kim and Khloe Kardashian were snapped climbing into water taxis in stilettos, followed by US talk show host Oprah Winfrey in an all-white outfit, including sensible trainers.
Tech magnate Bezos, 61, and Sanchez, 55, have reportedly invited about 200 guests to their multi-million dollar nuptials, which are expected to begin with an open-air soiree in the cloisters of the 14th-century Madonna dell'Orto church.
Sanchez, who arrived with Bezos on Wednesday, was spotted wearing a black dress with silver sequins — one of an alleged 27 outfits she will don during the festivities.
Protesters, some wearing carnival masks, demonstrated in St Mark's Square, accusing authorities of pandering to the super rich while the city drowns under tourists.
As police broke up the demonstration, Veneto's regional president Luca Zaia said the couple have upped their donation to the city from one to three million euros ($1.7 to $3.5 million).
Wedding guests and their bodyguards nipped up and down the lagoon, closely followed by paparazzi in boats rented at exorbitant prices by the world's media.
Police on jet-skis patrolled the canals around the Madonna dell'Orto as the party hour neared.
Guests spotted include Jordan's Queen Rania, British actor Orlando Bloom, US football player Tom Brady, Ivanka Trump — the daughter of US President Donald Trump — and American fashion designer Spencer Antle.
'Everyone wins'
Bezos and former news anchor and entertainment reporter Sanchez are staying at the Aman hotel, a luxury 16th-century palazzo on the Grand Canal with a view of the Rialto bridge.
They will exchange vows on Friday at a black-tie ceremony on the island of San Giorgio Maggiore, according to Italian media reports.
The wedding itself is expected to take place in a vast open-air amphitheatre on the island, which sits across from St Mark's Square.
The newlyweds will then be serenaded by Matteo Bocelli, the son of famed opera singer Andrea Bocelli, the reports said.
The celebrations will reportedly end on Saturday with a party at the Arsenale, a vast shipyard complex dating back to when the city was a naval powerhouse.
Some locals say the A-list guests and their entourages bring good business,
Adriana, 83, said "everyone wins" with the high-profile event, which has the city's famed luxury hotels booked out, and is likely to inspire others to marry in Venice.
And Samuel Silvestri, 55-year-old shopkeeper and resident, said the city's problem was day-trippers, "not the sort of tourism that turns Venice into a little Monte Carlo."
But critics have accused billionaire Bezos of using the UNESCO site as his personal playground.
Environmental activists have also pointed to the carbon footprint of the mega yachts and dozens of private jets bringing the rich and famous to the canal city.
It is "an excessive display of wealth and greed", 51-year-old American tourist Christine Baker told AFP. "I understand why people are upset."
Agence France-Presse