Transjordanian Highlands or just Transjordan
Transjordan was created in 1921.
Transjordan memorandum was created in 1922.
No. The Transjordan became the kingdom of Jordan.
Ikhwan raids on Transjordan happened in 1924.
The Emirate of Transjordan became the HASHEMITE KINGDOM OF JORDAN in 1946. It has retained that name ever since.
Israel and TransJordan
In 1922, the area that included modern Jordan was established called the Emirate of Transjordan. (It was semi-autonomous.) In 1946 on May 25th it became the independent Hashemite Kingdom of Transjordan. In 1950, the country was renamed the Hashemite Kingdom of Jordan . A link is provided to the U.S. State Department web page on Jordan.
Transjordan
The tribe of Reuvain settled in the Transjordan.
The British Mandate of Palestine was established in 1919 and was then partitioned into what is commonly known as the British Mandate of Palestine and the British Mandate of Transjordan (because it was on the opposite side of the Jordan River). This division came into existence because the British had promised the Hashemites (an important Arab family) a Kingdom for support in World War I. As a result, Transjordan fell under the control of the Hashemite Kings. When Transjordan became independent as Jordan in 1946, the Hashemites retained control of the country and still rule it to this day. The people of Jordan today are mixed. 40% of them consider themselves endemic Jordanians, which is to say that their ancestors lived in Transjordan before the independence because their ancestors lived in what remained in the British Mandate of Palestine until the Arab-Israeli War of 1948-9 (when presumably they fled to Jordan). It is important to note, however, that most Jordanians (endemic or Palestinian) consider themselves to be part of the same people: The Arabs of Bilaad Sham. (Bilaad Sham covers what is today Israel, Palestine, Lebanon, Syria, and Jordan, and is traditionally translated as "Greater Syria".)
Today Siam is called: Thailand.