Cádiz occupies the oldest continually inhabited site in Europe. Evidence of human habitation dates from the lower Paleolithic age, through the Neolithic and to the present. Early man is assumed to have crossed from Africa over what is today the Strait of Gibraltar. When the Phoenicians came along in the 12th century BCE and established their trading post, they named it Gadir. The name evolved over centuries of changing occupations (the Carthaginians in 520 BCE, the Romans in 206 BCE, the Visigoths in 410, then the Romans again in 550, the Visigoths again 572. The Moors in 711, then the Castilians in 1272.)
The geographical importance of the peninsula cannot be overemphasized. Cádiz sits at the northern tip of a long, very skinny peninsula that protects a large bay on the southwestern Atlantic coast of Spain. It is not far outside the Strait of Gibraltar, easily accessible from the Mediterranean. In the 16th century, the port boomed as trade with the Americas increased. Columbus sailed from Cádiz on his 2d and 4th voyages, and the Spanish Empire used Cádiz as its main port to ship riches from the New World. This of course meant that it was under repeated attack from pirates and other enemies; the English were a constant threat in the 16th and 17th centuries, as was France in the 19th. Several minor Spanish rebellions started here as well. But today the city is firmly Andalusian.