The country known in English as Burma, or Myanmar, has undergone changes in both its official and popular names worldwide. The choice of names stems from the existence of two different names for the country in Burmese, which are used in different contexts. The official English name was changed by the country's government from the "Union of Burma" to the "Union of Myanmar" in 1989, and still later to the "Republic of the Union of Myanmar". Since then, those name changes have been the subject of controversies and mixed incidences of adoption. Burmese names In the Myanmar language, Burma is known as Myanmar Pyi (မြန်မာပြည်). Myanmar Pyi is the written, literary name of the country, while Bama is the spoken name of the country. Burmese, like Javanese and other languages of Southeast Asia, has different levels of register, with sharp differences between literary and spoken language. Both names derive ultimately from the endonym of the largest ethnic group in Burma, the Burmans, also known as Bama or Mranma in the spoken register and in the literary register, respectively. As such, some groups—particularly non-Burmans minorities—consider these names to be exclusionary. "Bama" The colloquial name Bama is supposed to have originated from the name Myanma by shortening of the first syllable, from loss of nasal final "an" (), reduced to non-nasal "a" (), and loss of "y" () glide), and then by transformation of "m" into "b". This sound change from "m" to "b" is frequent in colloquial Burmese and occurs in many other words. Although Bama may be a later transformation of the name Myanma, both names have been in use alongside each other for centuries. King Mindon in the mid-19th century was the first to refer to himself as the king of the 'Mranma people', in an attempt to ethnicise his rule, at a time when his rule was largely confined to the Irrawaddy Valley and the Myanmar ethnic group. In 1930s, Ba Thaung, founder of the Dobama Asiayone (We Burmans Association), referred to the country as 'Bamapran' (ဗမာပြည်). He felt that the pronunciation of Mranma is "weak" and that of Bama is "strong". He also added that Bama refers to, not only the Mranma ethnic group, but all ethnic groups present in the country. "Mranma" The etymology of Mranma remains unclear. The "Burmans" who entered the central Irrawaddy river valley in the 9th century founded the Pagan Kingdom in