In a world first, members of 25 royal families are arriving to honour the world's longest-reigning monarch, His Majesty King Bhumibol Adulyadej

Never before have so many of the world's royal families appeared in the same place at the same time. The kings, queens and royal representatives of 25 nations are taking part in a grand celebration in Bangkok to honour His Majesty King Bhumibol Adulyadej's 60 years on the throne, and in the process will make this historic chapter in the Kingdom of Thailand a major part of global history.

Most of the royal guests began to arrive in Bangkok yesterday and they were all looking forward to attending a full ceremony today at 4pm at the Ananta Samakhom Throne Hall at the Royal Plaza to celebrate the 60th anniversary of His Majesty the King's accession to the throne. His Majesty the King has already been recognised as the world's longest-serving monarch.

Then, Their Majesties the King and Queen will accompany the royal guests to the Royal Navy Conference Hall to watch a royal exhibition and a royal barge procession, which is the highlight of the jubilee celebration. A total of 52 royal barges paddled by 2,200 oarsmen will sail down the Chao Phya River at about 6.30pm for the world to witness the unique royal ceremony and cultural heritage of Thailand.

Their Majesties the King and Queen will host a state dinner for the royal guests at the Chakri Throne Hall in the Grand Palace tomorrow to cap the celebrations, which began on June 8.

Sunny skies greeted the day's first arrival, Prince Henrik of Denmark, the consort of Queen Margrethe II. Henrik, who marked his 72nd birthday yesterday, was greeted at Bangkok International Airport by a smiling Her Royal Highness Princess Maha Chakri Sirindhorn, His Majesty the King's second daughter, who later also welcomed Grand Duke Henri, Luxembourg's head of state.

HRH Princess Sirindhorn's brother, His Royal Highness Crown Prince Maha Vajiralongkorn - Thailand's heir apparent - welcomed King Mswati of Swaziland, Cambodia's King Norodom Sihamoni and Japan's Emperor Akihito and Empress Michiko.

Royal visitors from Lesotho, Norway, Liechtenstein, Bhutan, Tonga, Belgium, Oman, Brunei, Malaysia and Kuwait were also scheduled to arrive later yesterday. Representatives of Sweden, Spain, Qatar, Monaco, the Netherlands, Jordan and the United Arab Emirates are due today.

On Friday, several hundred thousand Thais, clad in yellow shirts and with yellow flags in their hands, gathered at the Royal Plaza to honour His Majesty the King's 60th anniversary celebration on the throne.

Many could not hold back tears when they saw their beloved King waving to them from the balcony of the Ananta Samakhom Throne Hall. This grand event was broadcast around the world.

Rak Nai Luang, or Love the King, has been a phenomenon, with Thai family members wearing yellow shirts to display their love and respect for the King. Surakiart Sathirathai, the deputy prime minister and chairman of the organising committee for this celebration, said the royal guests and CNN are amazed with the immense popularity of the King among the Thai people.

Surakiart told the elite dignitaries who are witnessing the phenomenon first-hand that the outpouring of love is Thais' way of loving back a monarch who has been working tirelessly for the benefit of his people throughout the 60 years of his reign.