Desiderio Alberto Arnaz y De Acha was born on March 2, 1917 in Santiago, Cuba. His father Desiderio was mayor of Santiago and a wealthy property owner whose holdings included a cattle ranch, two dairy farms, and a villa on a small island in Santiago Bay. Desi's mother, the former Dolores de Acha, was the daughter of one of the founders of the Bacardi rum company. As a teenager, Arnaz was expected to attend college before embarking on a career in law and politics.

However, political unrest in Cuba dramatically changed the direction of Arnaz's life. In August 1933, the Arnaz home in Santiago was burned and ransacked. While Arnaz and his mother managed to escape to safety, his father, a newly elected congressman, was put in prison. While there, he was advised by the new chief of state, Fulgencio Batista, that he would be freed if he left the country. Promising to send for his wife (whom he'd later divorce) and son, Arnaz's father set out for Miami.

In June 1934, the 17-year-old Desi arrived in America and was greeted by his father, who had established an import-export company with two other refugees in Miami. To save money, father and son lived in the company warehouse and ate cans of pork-and-beans. They used baseball bats to ward off the rats that scurried through the building. After school, young Arnaz worked cleaning bird cages for a man who sold canaries on consignment in area drug stores.

During this time, Arnaz was recommended to a band-leader by a girlfriend's grandfather. Armed with a used guitar purchased for $5 from a pawnshop and a facility with the instrument - he'd used it often in Cuba to serenade the opposite sex - Arnaz persuaded his father to let him take this new $39-a-week job at the Roney Plaza Hotel. Xavier Cugat, the "king" of Latin dance music soon discovered the young musician. Upon graduating from high school and serving a stint in the Cugat orchestra, Arnaz debuted his own band in Miami Beach in December 1937.

The Desi Arnaz Orchestra won favorable reviews in New York and Miami. Collaborators, Lorenz Hart and Richard Rodgers, asked the young orchestra leader to audition for their upcoming Broadway musical Too Many Girls. Arnaz landed the part of the Latin American exchange student. Soon the 23-year-old was on his way to Hollywood to appear in the film version of the musical, starring 28-year-old studio actress, Lucille Ball.

"Lucy and Desi's first scene together in the movie Too Many Girls required him to take one glance at her and swoon dead away in ecstasy," commented Warren G. Harris in Lucy & Desi. "It didn't take much acting skill; by then, they were already in love in real life." The relationship was passionate and tumultuous from the start, punctuated by clashes of temper and jealousy. Many of the disagreements centered on Arnaz's flirtatious nature. Still, they came to care deeply for one another. Arnaz called her "Lucy" even though she had long called herself "Lucille." "I didn't like the name Lucille," Arnaz recalled in his autobiography. "That name had been used by other men. 'Lucy' was mine alone."

On November 30, 1940, Ball and Arnaz were married in Connecticut with a wedding ring purchased at the last minute from Woolworth's. "Eloping with Desi was the most daring thing I ever did in my life," Ball recalled, according to Lucy & Desi. "I never fell in love with anyone quite so fast. He was very handsome and romantic. But he also frightened me, he was so wild. I knew I shouldn't marry him, but that was one of the biggest attractions." Upon returning to California, the couple settled into a five-acre ranch in Chatsworth, just outside of Los Angeles. Mindful of the practice of naming their residence after themselves as actors Douglas Fairbanks and Mary Pickford had done, the couple decided on Desilu after eliminating such other possibilities as Arnaball, Ballarnaz, and Ludesi.

In May 1943, Arnaz received his draft notice to serve in World War II. Because of an injury, however, he saw only non-combat duty at Birmingham Hospital, 15 minutes away from Desilu. Convinced that Arnaz was being unfaithful to her, Ball filed for divorce in September of 1944. The divorce, though, was voided by a quick reconciliation.

Arnaz' officially shortened his name during his stint in the service (from Desiderio Alberto Arnaz y de Acha to Desi Arnaz). When his military service concluded, he returned to Hollywood, only to find his opportunities limited by his heavy accent. Despite critical acclaim for his performance in the movie Batman and gossip columnist Louella Parson's prediction that he'd be the next Rudolph Valentino, Arnaz found it difficult to secure significant parts. The new 22-piece Arnaz Orchestra, though, was getting favorable reviews, and Arnaz eventually landed a role in the movie Cuban Pete, in which he was touted as "The Rhumba-Rhythm King."

In 1948, Arnaz and Ball formed Desilu Productions to coordinate their various stage, screen, and radio activities. A year later, Arnaz asked Ball to marry him again - this time in an official Catholic ceremony. The ceremony was later played out again, albeit in a more fanciful manner, in an episode of I Love Lucy.