The Crown Prince of Jordan, Hussein bin Abdullah, will marry fiancee Rajwa Al Saif on Thursday in Amman.
Celebrations have already begun, with eager Jordanians and Saudis preparing to watch the festivities online or in person.
Here's what you need to know about the day and events leading up to it.
Who is Prince Hussein of Jordan?
The first-born son of Jordan's King Abdullah II and Queen Rania, Crown Prince Hussein, 28, will be married on Thursday.
He was named Crown Prince by royal decree in 2009. He was educated to secondary school level in Jordan, before studying international history at Washington's Georgetown University.
Prince Hussein then took an active role in his nation's military. He graduated from British royal military academy Sandhurst in 2017 and currently holds the rank of Captain.
His charitable foundation was established in 2015 and works with young people in Jordan to build their skills for the workplace and as citizens.
Prince Hussein often represents his father at important national events.
Who is soon-to-be Princess Rajwa Al Saif?
Prince Hussein's fiancee, Rajwa Al Saif, is a Saudi architect and the youngest of four siblings. Like Prince Hussein, she studied in her home nation before heading to the US for higher education.
She studied at Syracuse University.
Her family has strong ties to Saudi royal family.
What will happen on June 1?
Details of the day are still emerging but here's what we know so far:
- 5pm UAE time: Islamic marriage ceremony at Zahran Palace - with about 140 guests in attendance.
- Motorcade procession - The royal couple will be surrounded by red Land Rovers and BMW motorcycles on the journey.
- Wedding reception at Al Husseiniya Palace - 1,700 guests in attendance for royal banquet
- Performances by local and regional musicians
- 11pm UAE time : Wedding cake cutting
Who is on the guest list?
Heads of state and royals from around the world have already begun to arrive in Amman for the festivities.
Spain's former king Juan Carlos and wife Queen Sofia, Princess Catharina-Amalia of the Netherlands, Crown Princess Victoria and Prince Daniel of Sweden, and King Willem-Alexander and Queen Maxima of the Netherlands are among the royals expected to attend.
Whether the British monarchy will be in attendance has not yet been announced.
Prince Sebastien of Luxembourg is also expected. He attended the Sandhurst military academy in the UK with Prince Hussein.
Outside royalty, Jill Biden, wife of US President Joe Biden, confirmed she would be there, and has extended her visit to include Egypt and Morocco.
As yet, which leaders and royalty from the Arab world will be there has not been announced.
What events have already happened?
Prince Hussein and Ms Al Saif have attended pre-wedding events.
On May 22, she took part in a henna party with her mother-in-law to be, Queen Rania, and women from across Jordan. She wore a white abaya for the occasion made by Saudi designer Honayda Serafi.
Prince Hussein was honoured with a groom's party by his cousin Prince Omar bin Faisal. He mingled with family and friends, and members of the armed forces also attended, clapping and singing for him.
Crown Prince Hussein of Jordan celebrates groom shower
The night before the nuptials, King Abdullah hosted an elaborate dinner at the Madareb Bani Hashem at the Royal Hashemite Court for more than 4,000 Jordanians, where one of the country's national dishes, mansaf, was served.
"Our joy is complete with your presence," the king told the dinner party.
