The Romans had several provinces with Hispania in their names on the Iberian Peninsula. Modern Spain also encompasses such wide cultural diversity that the Spanish themselves speak of Las Espanas (The Spains). The country in its present form was never united under a single ruler until after the 1702-14 War of the Spanish Succession.

Spanish nationalism is strong in many regions, with former kingdoms such as Aragon largely content to be recognized as part of the Spanish nation-state. Asturias has its own language, but takes pride in its role as the birthplace of the Reconquista, or the taking back of Iberia from the Moors. Spanish nationalism was evident in recent years in Madrid in response to Catalonia's referendum.

Catalonia has long battled for independence. Its flag, the Senyera, is very similar to that of Aragon, to which it once belonged. The design is fabled to represent four bloodied fingers of Count Wilfred the Hairy being passed over a gold shield. Catalans were fairly happy with their situation until a court struck down the region's statute of autonomy in 2006 and support for independence grew.

Valencianismo, or Valencian nationalism, sprang out of the Renaixenca, an early-19th-century rebirth of the Catalan language, of which Valencian is just one variant. However, nationalist sentiment is not widespread in the region, which is home to Spain's Tomatina tomato-throwing festival. The Valencian Nationalist Bloc usually gets about 4 percent of the vote for the autonomous parliament.

The Balearic Islands — Mallorca, Ibiza, Menorca, Formentera — all speak variants of Catalan. Though there is a greater nationalist feeling on the islands than in Valencia, it is still more subdued than in Catalonia. Meanwhile, La Franja, a strip of Catalan-speaking land in Aragon, was split by the independence referendum, though most residents do not advocate self-determination for themselves.

Because of terror attacks by the ETA militant group, Basque separatists used to make the headlines far more often than Catalonia's independence movement. Separatists consider the Basque Country in France and Spain and the region of Navarre to be one nation. About a third of people want full independence, but most want more autonomy. A referendum proposed in 2008 was ruled illegal.

Although it was the birthplace of the centralist dictator Francisco Franco, Galicia has the strongest tradition of separatism after Catalonia and the Basque Country. Even Spain's mainstream national parties display a streak of Galicianism in the region. Perhaps as a result, starkly nationalist parties receive a lower share of the regional vote.

The Arabic name al-Andalus originally refers to the areas of the Iberian Peninsula that were under Moorish rule for 760 years. As Christians reconquered territories, the area known as Andalusia shrank southwards. Most Andalusians voted for autonomy after Franco died in 1975, but there is little appetite for full independence.

Hundreds of years ago, northern Spanish farmers would have traversed a much smaller, quainter Madrid as they herded their flocks of sheep toward the warmer winter meadows in the south. An agreement dating back to 1418 allows them to cross the city for a small fee. On Sunday, the bustling streets came to a standstill so the sheep could pass through.

The medieval tradition, giving farmers a rite of passage through the city, was renewed in 1994 with an annual festival that has become a major attraction for locals and tourists alike. Shepherds stop at the town hall to pay 50 "maravedies" — copper coins first minted in the 11th century — as payment for the crossing.

The Trashumancia sheep parade starts in the Casa de Campo, a former royal hunting ground that is now Madrid's largest park, then makes its way through the Puerta del Sol — the main square -— and finally past the Bank of Spain's headquarters.

The passage for the sheep was a timely reminder of the urban sprawl that threatens ancient grazing and migration rights. Much of Madrid was once undeveloped countryside, with woodland and grazing space that would have allowed a simpler passage for the flock.

Sunday's marching of around 2,000 sheep and goats was accompanied by musicians and dancers dressed in regional costumes that have been worn by rural workers for centuries.