Jordan’s Crown Prince Al Hussein bin Abdullah married Saudi architect Rajwa Al-Saif on Thursday in a palace ceremony attended by royals and other VIPs from around the world, as massive crowds gathered across the kingdom to celebrate the region’s newest power couple.

Rajwa is daughter to Khalid bin Musaed bin Saif bin Abdulaziz Al-Saif and Azza bint Nayef Abdulaziz Ahmed Al-Sudairi. The wedding drew a star-studded guest list including Britain’s Prince William and his wife Kate, US First Lady Jill Biden, Iraqi President Abdul Latif Rashid and his wife Shanaz Ibrahim Ahmed, Crown Prince Frederik of Denmark and Crown Princess Mary, King Philippe of Belgium, Crown Princess Victoria of Sweden, Cyprus first lady Philippa Karsera, and Queen Jetsun Pema of Bhutan.

The bride, wearing an elegant white dress by Lebanese designer Elie Saab, arrived at Zahran Palace in a 1968 Rolls-Royce Phantom V custom-made for the crown prince’s late great grandmother. The crown prince arrived earlier in full ceremonial military uniform with a gold-hilted saber.

The families and their guests gathered in an open-air gazebo decked with flowers and surrounded by landscaped gardens for a traditional Muslim wedding. The crowd erupted in applause after the signing of the marriage contract. Al-Saif will henceforth be known as Her Royal Highness Princess Rajwa Al Hussein, according to a royal decree.

Several miles away, a jolt went through a packed ancient Roman amphitheater as viewers watched the couple seal their vows and exchange rings on a wide screen. After several minutes of stillness, the crowd of some 18,000 people were on their feet, waving flags and shrieking with excitement at one of several viewing parties held across the nation.

Samara Aqrabawi, a 55-year-old mother watching the livestream with her young daughter, said the ceremony was more impressive than she imagined. “I wish for all mothers and fathers in Jordan and in the world to feel like they’re surely feeling,” she said of the king and queen.

The newlyweds later emerged from the palace in a white custom Range Rover escorted by several bright red Land Rovers, motorcycles and a military marching band — a nod to the traditional horse-mounted processions during the reign of the country’s founder, King Abdullah I.

The kingdom declared Thursday a public holiday so crowds of people could gather to wave at the couple’s motorcade amid a heavy security presence across the city. Tens of thousands of well-wishers attended free concerts and cultural events.

On Thursday morning, Saudi wedding guests and tourists — the men wearing white dishdasha robes and the women in brightly colored abayas — filtered through the marbled lobby of the Four Seasons Hotel in Amman.

“We are all so excited, so happy about this union,” said Noura Al-Sudairi, an aunt of the bride. “Of course it’s a beautiful thing for our families, and for the relationship between Jordan and Saudi Arabia.”

Excitement over the nuptials — Jordan’s biggest royal event in decades — has been building in the capital of Amman, where congratulatory banners of Hussein and his beaming bride adorn buses and hang over winding hillside streets. Shops had competing displays of royal regalia.

“She looks like such a princess that I think she deserves him,” Suhair Afaneh, a 37-year-old businesswoman, said of the bride, lingering in front of a portrait of Hussein in a dark suit.

Jordan’s 11 million residents have watched the young crown prince rise in prominence in recent years, as he increasingly joined his father, Abdullah, in public appearances. Hussein has graduated from Georgetown University, joined the military and gained some global recognition speaking at the UN General Assembly.

The wedding took place a week after Jordan’s 77th birthday. Combining tradition and modernity, the royal family introduced a wedding hashtag (#Celebrating Al Hussein) and omnipresent logo that fuses the couple’s initials into the Arabic words “We rejoice.”

Zahran Palace in Amman, where the marriage ceremony was held, hasn’t seen such pomp and circumstance since 1993, when, on a similarly sunny June day, Abdullah married Rania, who was born in Kuwait to Palestinian parents. Decades earlier, Abdullah’s father, the late King Hussein, sealed his vows in the same garden with his second wife, the British citizen Antoinette Gardiner.

In addition to the Prince and Princess of Wales, the guest list includes an array of foreign aristocrats and dignitaries, including senior royals from Europe and Asia, Saudi aristocrats, as well as US climate envoy John Kerry.

Both Rajwa and Kate wore gowns by the Lebanese designer Elie Saab, said a spokeswoman for the company, Maryline Mossino.

The motorcade drove through Amman to the Al Husseiniya Palace, a 30-minute drive away, for the reception. There, the newlyweds walked beneath an arch of swords and were welcomed with a traditional zaffeh, a lively musical procession featuring drums, dancing, singing and clapping.

The royals greeted more than 1,700 guests at the reception, which featured live music and a banquet. The celebrations were capped with a fireworks display that could be seen across the capital.

Jordanians from all walks of life shared an infectious excitement about the wedding.

“This is a really important day for my country, and those who are not Jordanian wouldn’t understand,” said Najwa Issamad, a 40-year-old nurse watching her teenage sons dance rowdily to pop wedding music blaring from their phones downtown. “It’s a time for all Jordanians to stop whatever we’re doing and say, let’s celebrate, let’s rejoice.”