On this day‬ in 1946 the head of an Italian crime family that was the predecessor to the Los Angeles crime family, passed away at the age of 72. His name was Rosario DeSimone, the father of Frank DeSimone (who became boss of the LA family in 1956).

Despite Rosario being a boss his reign didn’t last more than three years from 1922 until 1925, after he decided to call it a day and step into a legitimate business role.

On this day, 13th July 1946, Rosario DeSimone passed away at the age of 72, a largely overlooked figure whose significance to American organised crime history stretches far beyond the few years he spent at the helm of a powerful West Coast criminal organisation. DeSimone was the head of what would eventually evolve into the Los Angeles crime family, one of the most geographically expansive and influential Mafia outfits in the United States, and his story is one that deserves considerably more attention than history has typically afforded him.

Born in Sicily, DeSimone was among the waves of Italian immigrants who brought with them to America not only their traditions and culture, but also the deeply ingrained criminal structures of the old country. By the early 1920s, he had established himself as a commanding presence in the Los Angeles underworld, taking the reins of the city's Italian crime organisation around 1922. His tenure as boss, however, proved to be a brief one. By 1925, DeSimone had made the unusual decision to step away from the criminal life entirely, transitioning into a legitimate business role — a move that was virtually unheard of amongst men of his standing during that era.

His three-year reign coincided with a turbulent and transformative period in American criminal history. Prohibition had thrown open the doors to extraordinary profits for organised crime across the country, and figures like Al Capone were cementing their iron grip on cities such as Chicago, whilst the foundations of what would later become the national crime syndicate were being quietly laid by men like Lucky Luciano. DeSimone's Los Angeles operation existed within this broader landscape, functioning as part of the emerging national network of Italian-American criminal power that was steadily spreading from coast to coast.

Perhaps DeSimone's most enduring legacy lies not in his own criminal career, but in the dynasty he left behind. His son, Frank DeSimone, would go on to become boss of the Los Angeles crime family in 1956, carrying the family name into a new and considerably more turbulent chapter of mob history. Frank would also represent Los Angeles at the notorious 1957 Apalachin Meeting, the gathering of mob bosses that blew the lid off the existence of a national crime syndicate and shocked law enforcement across America.

Rosario DeSimone may have chosen a quiet exit from the life he once led, but the shadow he cast over Los Angeles organised crime proved remarkably long-lasting, shaping the city's underworld long after his death.