| King Rama I | King Rama II | King Rama III | King Rama IV | King Rama V | King Rama VI | King Rama VII | King Rama VIII | King Rama IX |

THE FULL FAMILY TREE OF THE CHAKRI DYNASTY IS complex and at times perplexing. Each king and queen is known by several different names and titles, some posthumously conferred. Many of the princes and princesses have more than one title, and alterations can be made, not only to their rank but also to the terms describing their relationship to the reigning monarch, which change from reign to reign. These ranks and titles are finely graded, revealing nuances which explain the exact rank and relationship to the king of the individual prince or princess.

This hierarchy of rank and title is unique to Thailand [although a similar, but less complex system exists within the royal family of Cambodia] and is the most elaborate system of royal rank to be found in any country in the world. There are three distinct ranks of prince and princess, but even within each rank there are finer distinctions which divide the members into different sub-groups. The three main ranks are as follows:-

• The Chao Fa This title is usually restricted to the children of a king or queen. There are at present only five Chao Fa living , one prince and four princesses; they include the present Crown Prince, two daughters of His Majesty King Bhumibol Adulyadej, his sister, and the daughter of His late Majesty King Vajiravudh [Rama VI]. Another daughter of His present Majesty, the former Princess Ubol Ratana Rajakanya, who relinquished her royal title in 1972, was also of this rank.

• The Phra Ong Chao--there are two specific grades within this rank, those Phra Ong Chao who have the additional word Chao within the preamble to their title, and those who do not :
  

  • [Phra Chao Vorawongse Ther] Phra Ong Chao--Prince or Princess and Royal Highness.
    
  • [Phra Vorawongse Ther] Phra Ong Chao--Prince or Princess and Highness.
    
  • The Phra Ong Chao nowadays are always the grandchildren of a king--three of the present King's grandchilden are of this rank, and the other 10 living Phra Ong Chao are all grandchildren of King Chulalongkorn [ Rama V ], from senior lines of descent.

• The Mom Chao--this is the lowest of the royal ranks and the usual title of a grandchildren of a king [except where raised to be a Phra Ong Chao]; in the case of a great-grandchild of a king who is a Mom Chao then he or she is the child of a Phra Ong Chao prince, who is himself of a grandchild of a king. The Mom Chao are known in English as Prince or Princess and Serene Highness. There are at present some 150 Mom Chao living--53 are grandchildren or great- grandchildren of King Chulalongkorn [Rama V], 82 are grandchildren or great-grandchildren of King Mongkut [Rama IV], 14 are grandchildren of the last Maha Uparaja [ or Deputy King] and one, the last surviving grandchild of Second King Pinklao, who died in 1866. They are for the most part elderly and in the years to come their number will be much diminished. In the early part of this century the total of Mom Chao was much higher, numbering several hundred, and including grandchildren of King Rama III, King Rama II and even King Rama I, as well as numberous grandchildren of the earlier Maha Uparaja. By the end of the century it is likely that there will only be several dozen Mom Chao left within the Royal Family.

  The great-grandchildren of a king do not bear royal rank but are entitled to use the title of Mom Rajawongse, which is not translated into English. The great- great-grandchildren bear the title of Mom Luang. Subsequent generations in the male line of decent from a king have no titles, but may add the dynastic surname of "na Ayudhya" to the surname of the branch of the Royal Family from which they descend.

The Royal Family is divided into 131 different branches. Each son of a king, or Maha Uparaja, who founded a family, was granted a surname by King Vajiravudh [Rama VI]
Several more were granted during the reign of his successor, King Prajadhipok [Rama VII]. As part of the 60th birthday celebrations of His Majesty King Bhumibol Adulyadej, representatives of each branch will gather at the Chitralada Villa of Dusit Palace in a ceremony that has not been performed for many years. They will be received in audience by the King in the Dusidalai Hall and will be grouped strictly according to the seniority of their descent from the previous kings of the Chakri Dynasty. The task of deciding the order of precedence is not an easy one and assistance is given by the chairman of the family association of the Chakri Dynasty , who keeps careful track of the whereabouts of each branch and its members, ensuring that they are informed of the gathering and at the same time checking that no imposters lay claim to an unverified descent. This is rare, though from time to time "pretenders" do emerge and assume the name of some remote line of descent of the Royal Family.

The names of the Kings of the Chakri Dynasty are long and complex and take various forms. It is customary that the sovereign's name is longer than that of anyone else in the Kingdom and the full royal name and title, as inscribed on a golden name plate at the time of the coronation, is impractical for daily use. Several different systems for naming the kings have developed over the years. In the reign of King Rama III it was decided that the first two kings of the Chakri Dynasty should be accorded a personal name. Hitherto, people had referred to these two kings as "The King of the Foremost Reign" and "The King of the Middle Reign." King Rama III had two large golden Buddha images made and dedicated them to the first two kings and decreed that they be known as King Buddha Yot Fa and King Buddha Loet La. He himself became King Nang Klao. His successors became King Chom Klao [Mongkut] , King Chula Chom Klao [Chulalongkorn] ,King Mongkut Klao (Vajiravudh) and King Pok Klao [Prajadhipok]. Abroad and to foreigners living within the country these kings were known by other names - the personal name they had before their accession - hence King Mongkut, King Chulalongkorn, King Vajiravudh and King Prajadhipok, and this custom was continued during the two subsequent reigns with King Ananda Mahidoland King Bhumibol Adulyadej.

One of the fascinations of the Thai system of royal rank and title is the subtlety with which the title of a member of the Royal House reveals an exact degree of rank. Apart from the three distinct princely ranks mentioned earlier there are other features of royal titles which further define the holder's true position in the royal hierarchy. In the titles of all princes and princesses of Phra Ong Chao and Chao Fa rank are to be found certain words which also indicate their relationship to the reigning King. These form part of the preamble to the title and in the case of the closest royal relatives indicate the exact relationship. More distant relatives have a word indicating to which group of princes and princesses they belong. Thus the son of the reigning king will be Somdetch Phra Chao Lukya Ther Chao Fa, the daughter Somdetch Phra Chao Luk Ther Chao Fa, the elder brother Somdetch Phra Chao Piya Ther Chao Fa, the younger brother Somdetch Phra Chao Nongya Ther Chao Fa, and so on. These relationship terms change from reign to reign, with the children of one king becoming, perhaps the elder and younger brothers and sisters of the next king. The system applies equally to deceased members of the Royal Family and the late younger brother of a reigning king will become the late uncle of his successor and his title will be altered accordingly. There is thus a gradual and evolving pattern of change within the system of royal titles.

Another feature of the precise definition of rank can be found among the regalia of the most senior members of the Royal Family. When they receive their titles they are presented with a set of regalia, which, should their title be high enough, will include a multi-tiered royal umbrellas, or parasol. These royal umbrella are of different levels, usually of five, seven or nine tiers. Only a crowned king possesses a nine-tiered umbrella [prior to his coronation he is entitled to one of seven tiers]. The holders of seven tier umbrellas form a special group within the Royal Family, those whose titles contain the words "Somdetch Phra Baromma" and at the present time these include only four people, Her Majesty the Queen, H.R.H. the Crown Prince, H.R.H. the Princess Mother and princesses of Cho Fa rank are entitled to royal umbrellas of five tiers. These royal umbrellas reveal the rank of the holder and as such can form part of their insignia or coats-of-arms and at their cremations are to be found suspended above the crematorium, or above their urns at their lyings-in-state.