As soon as Karthika Thirunal turned 16, it was decided to get her married. Usually, the
Koyi Thampurans were chosen as bridegrooms for Travancore Princesses and Queens. According to
Uthradom Thirunal, Maharajah
Sree Chithira Thirunal and
Sethu Parvathi Bayi ignored the superiority of Koyi Thampurans and got her married to a young aristocrat named P.R. Godavarma Raja of Poonjar Palace. The Maharajah felt that it was fine to make a different choice so as to find a suitable spouse for his sister and for the first time chose a bridegroom from the Poonjar Royal House. When P.R. Ramavarma Raja, (husband of Karthika Thirunal's maternal aunt), visited Kowdiar Palace, he put forward the name of his younger brother Godavarma Raja (Col.
G. V. Raja) as a prospective bridegroom for Karthika Thirunal. Godavarma Raja who later attained immortal fame as the
King of Kerala Sports and Tourism, at the time of the proposal was studying in Madras for attaining a Degree in Medicine. The couple met each other in 1933. Godavarma accepted the wedding proposal for Karthika Thirunal's hand and discontinued his education there. Karthika Thirunal's family too approved, and the wedding was thus announced. It was the first time a Travancore Princess married some one other than a
Koyi Thampuran. Poonjar Royal Family is believed to be the descendants of
Pandya Dynasty. The preparations for the
Pallikettu (wedding of a Travancore Princess)began in 1933 itself. Huge wedding venue was created at
Sundara Vilasom Palace. Many prominent Indian Royals were invited for the wedding and the wedding was a lavish affair. The wedding of 17-year-old Karthika Thirunal and 26-year-old Godavarma Raja took place on 24 January 1934. The royal couple stayed at
Kovalam for their honeymoon and it was during this time, Godavarma Raja, smitten by the beauty of the place, decided to develop and promote Kovalam as a tourist destination. After their wedding,
G. V. Raja joined the Travancore State Force (Army) and served as a
Lt. Colonel and as one of the commanding officers of the Nair Brigade (Travancore King's Bodyguards). The couple had four children, Elayarajah (Crown Prince) Avittom Thirunal Rama Varma (1938–1944, died at the age of six of a rheumatic heart condition), Pooyam Thirunal Gowri Parvati Bayi (1941),
Aswathi Thirunal Gowri Lakshmi Bayi (1945) and Sree
Moolam Thirunal Rama Varma (1949), the Titular Maharajah of Travancore and the Head of Travancore Royal Family & Supreme Guardian/Custodian of Sree Padmanabhaswami Temple. In the memory of his late nephew, Prince Avittom Thirunal, Maharajah
Chithira Thirunal Balarama Varma built the SAT Hospital in Trivandrum. ==Full title==