The Principality of Monaco covers just 473 acres.
Let's go back in time...Monaco's present ruler, Prince Rainier III, traces his ancestry to Otto Canella, who was born in 1070. The Grimaldi dynasty began with Otto's great-great-great-grandson, Francesco Grimaldi, also known as Frank the Rogue. Expelled from Genoa, Frank and his cronies disguised themselves as monks and seized, in 1297, the fortified medieval town known today as Le Rocher (The Rock). Except for a short break under Napoléon, the Grimaldis have been here ever since, which makes them the oldest reigning family in Europe. On the Grimaldi coat of arms are two monks holding swords (look up and you'll see them above the main door as you enter the palace).
Back in the 1850s, a Grimaldi named Charles III made a decision that turned the Rock into a giant blue chip. Needing revenues but not wanting to impose additional taxes on his subjects, he contracted with a company to open a gambling facility. The first spin of the roulette wheel was on December 14, 1856. There was no easy way to reach Monaco then—no carriage roads or railroads—so no one came. Between March 15 and March 20, 1857, one person entered the casino—and won two francs. In 1868, however, the railroad reached Monaco, filled with wheezing Englishmen who came to escape the London fog. The beneficial effects—both for the Englishmen and the economy of Monaco—were immediate. Profits were so great that Charles eventually abolished all direct taxes.