The Na Bangxang lineage is one of the lineages of the Sukhothai dynasty of the Ayutthaya kingdom, the Phra Ruang dynasty (the Sukhothai dynasty) of the Sukhothai kingdom, the Singhanawat dynasty (the Singhanavati dynasty) of the Yonok Chiang Saen region, and the Haryanka dynasty of the Magadha region in ancient India. In addition, the Na Bangxang lineage is one of the queens' lineages of the Chakri dynasty and it is one of the Bangxang collection of the lineages of Her Majesty Queen Amarinthara (Queen Amarindra of Siam), the queen of His Majesty King Buddha Yodfa Chulaloke the Great (King Rama I).
The Na Bangxang lineage is one of Thailand’s lineages that have been traced back the farthest. It can currently be traced back to at least 23 generations. Let "A < B" mean "A was B's father", then King Phangkharat < King Phrom the Great < King Sri Now Nam Thum < King Sri Indraditya < King Ram Khamhaeng the Great < King Maha Thammaracha Leuthai < King Maha Thammarachathirat Loethai < King Maha Thammarachathirat (Khun Phiren Thorathep) < King Ekathotsarot < Prince Saen < Prince Bunsa < Prince Nop < Phraya Samut Songkhram < Phraya Uthaitham (Khun Chai Klang) < Phraya Mahissararatchasamphan (Kun) < Mr. Ngim Na Bangxang < Mr. Jam Na Bangxang < Mr. Saard Na Bangxang < Prof. Dr. Erb Na Bangxang, M.D., and let "A << B" mean "A was B’s patrilineal ancestor", then a king of the Haryanka dynasty of the Magadha region in ancient India < King Singhanawat (Singhanavati) << King Phangkharat, so, as much information as shown, the Na Bangxang lineage can currently be traced back to at least 21 generations.
In 1630, Prince Plai and Prince Saen, who were the first son and the second son, respectively, of King Ekathotsarot (King/Prince White), the known younger brother of King Naresuan the Great (King/Prince Black) who had no sons, escaped from royal danger to the Bangxang district of the Ratchaburi city and then settled there (Currently, the district is the Samut Songkhram province. Formerly, it centered at the current Bangxang subdistrict of the current Amphawa district of the current Samut Songkhram province.). Since they were royalties, they had many servants and plenty of assets; so they conducted waterborne commerce, in the Bangxang district. They were very wealthy, so townspeople praised their lineage as the Bangxang wealthy/millionaire lineage.
In general, the Bangxang wealthy lineage was (British English: were) arrogant, pompous, and preserved their heredity as those born into the Kshatriya caste do (as the origin of Buddha’s Shakya lineage did). - Under the Hindu caste system, a Kshatriya is a ruler or warrior. In general, the Bangxang wealthy lineage married one another. Their females had to marry within the same lineage. Their males could marry outsiders. Consequently, the origin of a patrilineage of the Bangxang wealthy/millionaire lineage was either Prince Plai or Prince Saen.
In addition, the Na Bangxang lineage is one of the queens' lineages of the Chakri dynasty. It is one of the Bangxang collection of Queen Amarinthara's lineages. The collection consists of the following five lineages: Xuto, Saengxuto, Sawasdixuto, Boonnak, and Na Bangxang. Prince Thong and Princess San were Her Majesty Queen Amarinthara's father and mother; they were Prince Saen's and Prince Plai's patrilineal descendants, respectively; and had the following ten children:
Princess Thong Yoo
Her Majesty Queen Amarinthara
Princess Chee Pho
Three of the children are the origins of the Bangxang collection of Her Majesty Queen Amarinthara's lineages. They are
Prince Xuto, the origin of the Xuto, Saengxuto, and Sawasdixuto lineages;
Princess Nuan, who was given her husband's family name (surname, especially British English) Bunnag; and
Princess Kaew, who were married to Phraya Samut Songkhram (Phraya Samut Songkhram’s and Chao Khun Ying Kaew’s descendants’ family name is Na Bangxang.).
Butsakorn Na Bangxang, The “Na Bangxang” Queen’s Lineage (Bangkok: Amarin; September 29, 2004) 71 pages. This book is a funeral remembrance of Professor Erb Na Bangxang, M.D., Knight Grand Cordon (Special Class) of the Most Exalted Order of the White Elephant, Knight Grand Cordon (Special Class) of the Most Noble Order of the Crown of Thailand, Knight Commander (Second Class, lower grade) of the Most Illustrious Order of Chula Chom Klao.
Thep Soonthornsaratoon, A History of the “Bangxang” Queen’s Lineage (Bangkok: Phra Narai, 1997) 232 pages.