More than 100,000 well-wishers are estimated to have lined the royal wedding procession route as police effectively formed a ring of steel around Windsor Castle in the high-security operation.
Police marksmen and airport-style scanners helped secure Prince Harry and Meghan Markle's wedding on Saturday, with the costs expected to run into the millions.
The Royal Borough of Windsor and Maidenhead estimated "just over" 100,000 fans watched the procession along the route and British Transport Police reported that 20,000 passengers had streamed through the town's stations by 9.40am.
Officers with sniper rifles were spotted on roofs around the town in what was one of the largest public events handled by Thames Valley Police.
In a bid to ward off vehicles being used as weapons, as seen in the terrorist atrocities committed on London and Westminster bridges, metal barriers were installed around the Berkshire town.
Armed officers, dog handlers and mounted police were on the ground while, in the air, drones were banned from flying over the estate and aircraft restricted from flying below 2500 feet.
While confetti was not banned, police asked fans to not throw the "potential security risk" or other items throughout the day, particularly during the procession.
Along with the security scanners, visitors were warned not to leave belongings unattended and that they could be subjected to inspections.
The operation was in progress months before the big day itself and police were manning barricades outside the castle and sniffer dogs performing checks on Friday.
The US actress was a big draw for American fans as well as Britons and police correctly estimated ahead of the event the number of revellers that would join festivities.
Almost every Thames Valley Police officer was working on Saturday as Harry and Meghan's 600 guests attended their wedding, 200 of which will celebrate at an evening reception hosted by the Prince of Wales at Frogmore House.
The security operation for the wedding of the Duke and Duchess of Cambridge cost police more than PS6 million, according to figures revealed in April, with nearly half of that spent on overtime costs alone.
The cost of the royal spectacle cannot yet be confirmed.
No arrests in relation to Windsor's wedding celebrations had been made by 2pm.
