What's behind the downfall of Thailand's Princess Srirasmi?

Princess Srirasmi Akrapongpreecha is Crown Prince Vajiralongkorn's third wife

The downfall of Princess Srirasmi, the wife of Thailand's Crown Prince Vajiralongkorn, has been both dramatic and unusually public.

Seven of her relatives have been arrested, and accused of misusing their royal status to amass vast wealth and carry out numerous abuses.

The crown prince himself has now made the disgrace official by ordering her family to stop using the name Akrapongpreecha, which he gave them after he married her in 2001. The king and the crown prince both have this privilege, akin to knighthoods in the UK.

So has Princess Srirasmi lost her royal status?

The monarchy is central to Thai society and has a pivotal position in the country's political order

Interestingly, the crown prince has not revoked her royal title, "Mom", which translates roughly as "princess", nor yet her use of the royal family's name, Mahidol na Ayutthaya.

These are officially bestowed by King Bhumibol Adulyadej, and it would need his approval for them to be revoked. However if, as expected, the crown prince divorces Princess Srirasmi, she will almost certainly lose both titles. The future status of her nine-year-old son by the prince, Dipangkorn, will depend on his father's wishes.

Titles matter a great deal in status-obsessed Thailand, in particular when it comes to those with a claim to the throne.

What does Thai law say about the succession?

The pivotal position of the monarchy in Thailand's political order makes the succession a sensitive issue

The 1924 Palace Succession Law, enshrined in subsequent constitutions, follows the principle of primogeniture, meaning Crown Prince Vajiralongkorn is the designated heir to King Bhumibol, and his own sons should inherit the throne after him, ranked by age.

However, the law also gives reigning kings considerable sway in choosing their own successor - and an amendment to the constitution now allows the possibility of a female successor.

Does the crown prince have any other male children?

It is believed that Crown Prince Vajiralongkorn had a baby boy this year with his current mistress

The crown prince has four sons by his second marriage, whom he disowned in 1997 when he severed all ties with their mother, Yuvadhida Polpraserth.

At the time the crown prince stated that they had renounced all their royal titles. But the palace continues to recognise their right to use the title HSH, or His Serene Highness, even though the boys, now grown up, are banished from Thailand and live in the United States.

That leaves some doubt over where they sit in line to the throne, even though most commentators believe they are no longer considered possible successors.

It is widely believed that the crown prince may have had another baby boy this year with his current mistress, who is likely to become his next wife.

Why does all this matter so much?

The world's longest-reigning monarch, King Bhumibol has been on the throne in Thailand since 1946

The issue is critical in a country where the monarchy is considered pivotal to political stability, and where King Bhumibol, who turns 87 this week, is in such frail health.

Crown Prince Vajiralongkorn appears to be sorting out his personal affairs before the succession, so that he can choose who will be his queen, and who will eventually succeed him.