Romero was born 3 March 1897, one of three children born to Francisco Romero Sr., mayor of Tanjay, Negros Oriental from 1909 to 1916 and later a member of the Provincial Board of Negros Oriental, and Josefa Calumpang Muñoz, daughter of Tanjay gobernadorcillo Don José Teves Muñoz and Doña Aleja Ines Calumpang.

His mother died in a stampede that occurred on 24 December 1906 while midnight mass was being celebrated at the St. James the Greater Parish in Tanjay.

[3] After graduation, he enrolled at the University of the Philippines College of Law but had to temporarily postpone his studies due to ill health.

[3][4] On 17 July 1918, Romero and Carlos P. Romulo led the first student protest march at UP to show support for university president Ignacio Villamor who was then being criticized and defamed by newspaper columnist Manuel Xerez Burgos of The Manila Times.

[5][6] In April 1922, Romero was a delegate to the World Student Christian Federation conference held at Tsinghua University in Beijing.

He was reelected to the 10th Philippine Legislature and remained as majority floor leader, which only lasted until the following year when it was effectively replaced by a unicameral national assembly as a result of the 1935 Constitution.

He was majority floor leader from 1935 to 1938, and was concurrently chairman of the Congressional standing committees on rules and on education, and ex-officio member of the Board of Regents of the University of the Philippines.

[2][10][11] In 1939, during a meeting convoked by President Quezon, he called for an indefinite suspension of the planned 1946 Philippine independence, which was under the threat of World War II.

[15][16][17][18][19] In 1917, after finishing his undergraduate degree, he worked as an assessor at the Bureau of Customs but only stayed on for four months due to conflicts in schedule with his classes at law school.

[11][20] On 20 August 1949, Romero was appointed by Elpidio Quirino as envoy extraordinary and minister plenipotentiary of the Philippine foreign service.

The legation was later upgraded to embassy status with Romero serving as the first ambassador extraordinary and plenipotentiary of the Philippines to the Court of St.

[23] While ambassador, he headed the Philippine delegation, which included senator José Locsin, to the 1953 International Sugar Agreement convened by the United Nations in London.

[24][25] In 1953, he ended his tour of duty when he resigned to become the representative of the Philippine Sugar Association (PSA) to Washington for whom he was longtime executive officer and secretary-treasurer, and later president.

They had seven children: On 17 December 1941, he was aboard the ill-fated SS Corregidor when it hit a mine off the coast of Manila Bay where his cousin Juanito Calumpang, an academic supervisor of the Department of Education, and his daughter died.