Most Thais have never witnessed a coronation -- it has been almost 70 years since the last one, when the young Bhumibol Adulyadej was crowned in 1950.

But while Bangkok may have changed from a slow-moving capital to a bustling modern city, the spectacular coronation of King Maha Vajiralongkorn will tack closely to intricate traditions.

From sacred water purification and a diamond-encrusted crown to a grand procession, here are five rituals to look for when King Vajiralongkorn is crowned Rama X this weekend.

Royal purification

The entire coronation ceremony extends over three days from May 4-6, but Saturday is the one to watch.

The first day rituals represent a symbolic transformation from the human to the divine for the monarch.

First, at the auspicious time of 10:09 am - some speculate the hour reflects Rama X's reign, while '9' in Thai sounds like the word for 'progress' - the royal purification ceremony begins.

Wearing a white robe, the king will enter a pavilion at the Grand Palace, where he will be doused in sacred water from five rivers and four ponds in Thailand.

In the distant past water was collected from specific rivers in India, reflecting the influential blend of Hindu and Buddhist cosmology on the coronation.

Hindu Brahmins as well as the country's most senior Buddhist monks will be present.

Coronation practices can be traced back thousands of years to ancient India, according to Komkrit Uitekkeng from Silpakorn University.

The crown

Not long after royal purification rites, the king proceeds to the Baisal Daksin Throne Hall where he receives sacred water from eight directions.

Symbolically that "means he has received legitimacy from all directions of the kingdom", Komkrit said.

He ascends the Bhadrapitha Throne, where in regal robes he sits under a Nine-Tiered Umbrella of State.

Brahmins will hand the monarch the royal regalia, including a wooden sceptre inlaid with gold, a precious stone-encrusted sword believed to have been found in a lake in northern Cambodia, slippers, and a whisk made from yak's hair.

The Great Crown of Victory is the centrepiece.

Tiered, gold and weighing 7.3 kilograms, it has a diamond from India at the top. Vajiralongkorn will personally place the crown on his own head.

He then issues his first royal command, which will be similar in meaning if not in wording to previous members of the Chakri dynasty, founded in 1782. 

His father Bhumibol's first royal command was: "I will reign with righteousness, for the benefit and happiness of the Siamese people."

The audience

On Saturday afternoon, the newly-crowned king is set to grant a "grand audience" to members of the royal family, the privy council, the cabinet and senior officials.

There participants, a who's who of the powerful, wealthy and influential in junta-run Thailand will offer their "best wishes" to the monarch.

Two hours later the king will visit the Temple of the Emerald Buddha, the most sacred space in Thailand, which on normal days is thronged with tourists.

He then symbolically moves into the Royal Residence.

The procession

The main element of Sunday's ceremonies, streets across Bangkok's historic heart have been blocked off in preparation for this moment.

At 4:30 pm on May 5, Vajiralongkorn will sit on a royal palanquin carried by soldiers dressed in colourful traditional garb.

A 21-gun salute will kick off the procession.

Some 200,000 people are expected to line the seven-kilometre route around the city, braving the city heat.

The procession "gives the people a chance to witness for themselves that we have a new king," said Tongthong Chandransu, a researcher of royal ceremonies, who plans to watch the "great experience" in person.

It will also take the king to a number of important temples in the city where he will pray before images of the Buddha.

For many Thais, this will be their first real glimpse of a king who spends much of his time abroad.

Meet the people

On the last day of the ceremony Rama X will appear on the balcony of Suddhaisavarya Prasad Hall in the Grand Palace at 4:30 pm "to receive the good wishes of the people".

An hour later, diplomats will be given an audience at the Grand Palace.

This is the only time during the ceremony that representatives of foreign governments will greet the king.