The citizens of Monaco have never been allowed to gamble in the casino that made their country famous. That rule goes back to the beginning, when the House of Grimaldi was nearly broke. In 1848 the towns of Menton and Roquebrune declared independence, taking with them the olive oil and fruit taxes that funded the state. Prince Florestan froze. His wife, Princess Caroline, looked to the spa and gambling resort at Bad Homburg in Germany and decided Monaco would copy it: drain wealthy foreigners at the tables while keeping locals away from the house edge.

The first attempts flopped. A temporary casino opened in December 1856 in a villa with no roads leading to it, no hotels, and no marketing, and the concession passed from one overwhelmed manager to the next. This episode follows how Caroline finally landed François Blanc, the man behind Bad Homburg, and how his money, railways, and rebranding turned a spot called The Caves into Monte Carlo, a stage for famous winning streaks, costly superstition, and a name borrowed by physics.

• After Blanc refused her offer, Caroline befriended his ailing wife and kept insisting that Monaco’s mild climate was the cure. By 1863 he had taken over with 15 million francs in capital and a 50-year concession.
• Blanc had lent nearly five million gold francs to help finish the Paris Opera, which let him call in architect Charles Garnier to add the Beaux-Arts concert hall facing the sea.
• Breaking the bank meant emptying one table’s reserve of chips, at which point the croupier draped it in black cloth until more funds arrived from the vault.
• In 1873 British engineer Joseph Jagger hired six clerks to log every winning number, found a biased wheel favoring nine numbers, and bet on its mechanical flaw.
• In the summer of 1913 a roulette ball landed on black 26 times in a row while gamblers lost millions of francs betting that red was due.