Rama X, King of Thailand, has named a royal concubine, or lesser consort. This is the first such appointment in nearly a century.
Since the death of Rama VI in 1925, the Thai kings have either been officially monogamous (Rama VII and Rama IX) or unmarried (Rama VIII).
The present King, who succeeded his late father in 2016, married his longtime companion, the former Suthida Tidjai, now Queen Suthida, on 1 May, 2019. She is his fourth official spouse, in sequence, and was crowned queen alongside him days later. Today he formally elevated Sineenat Wongvajirapakdi to the rank of Chao Khun Phra, which translates as Royal Noble Consort, in a ceremony at the Grand Palace in central Bangkok. Both ladies previously held the rank of general in the King's elite bodyguard corps.
In the old days, Thai kings had up to several dozen wives and lesser consorts, whose titles were distributed according to 16 different ranks. Titles and ranks were strictly regulated according to the women's birth, closeness to the King, whether they had born him children, etc.
There is an excellent Wikipedia article on Thai royal and noble titles, which contains a helpful table of the royal consorts' ranks. You can find it here: https://en.wikipedia.org/wiki/Thai_royal_and_noble_titles
To illustrate, Queen Suthida presently holds the second highest rank and Lady Sineenat holds the eleventh. Traditionally, the latter's rank of Chao Khun Phra was the highest to which a consort of common birth could aspire. That is evidently no longer true, since Queen Suthida was also born a commoner, so the reasons for the choice of this rank for Lady Sineenat are unclear.
There is no word yet on how the new consort will be styled in English. I'm going with "Lady" Sineenat for now. An article from Khao Sod English, the online English version of one of Thailand's leading daily newspapers, specifies that the Chao Khun Phra rank does not require use of Rajasap, the formal court language used to address and refer to members of the royal family, so Lady Sineenat will presumably not have the predicates Her Majesty (HM) or Her Royal Highness (HRH). Her Excellency? Her Grace? Her Ladyship? We'll see!
To read the Khao Sod English article about Lady Sineenat's appointment, go here: http://www.khaosodenglish.com/news/2019/07/30/rama-x-names-first-royal-consort-in-almost-a-century/
Photo credit -- Khao Sod English via Wiki Commons