Dalmatia is a colorful region on the eastern coast of the Adriatic Sea, the origin of the Dalmatian dogs.
Ancient Dalmatia
The Roman Empire occupied Illyria in year 168 B.C. forming the province Illyricum, which was split into Pannonia and Dalmatia in year 10 A.D.
Roman Dalmatia spanned the whole area of the eastern coast of the Adriatic Sea and most of the Dinaric Alps on the continent. It bordered Italia and Noricum in the north, Pannonia in the northeast, Moesia in the east and Macedonia in the south.
Dalmatia got its name after the Illyrian tribe called Dalmats. The Illyrians weren't just some random barbarians: since at least 1225 B.C., they had a kingdom which united several of the tribes. Unfortunately for them, they also had powerful enemies: Alexander the Great of Macedonia in the east, and Rome just across the Adriatic, which eventually conquered them completely.
The capital of the Roman province was Salona (today's Solin). Emperor Diocletian made Dalmatia famous by building a palace for himself a few kilometers south of Salona, in Aspalathos (today's Split).
Other cities were
Tarsatica (Trsat, now part of Rijeka),
Senia (Senj),
Vegium (Karlobag),
Aenona (Nin),
Iader (second-largest city of Zadar),
Scardona (Skradin, just north of Šibenik),
Tragurium (Trogir),
Aequum (Čitluk near Sinj),
Oneum (Omiš south of Split),
Issa (Vis),
Pharus (Hvar),
Corcyra (Korčula),
Narona (tiny town of Vid near present day Metković),
Epidaurus (Cavtat just south of Dubrovnik),
Rhizinium (Risan),
Acruvium (Kotor),
Dulcigno (Ulcinj),
Scodra (Shkodër),
Dyrrachium (Durrës) and others.
As you can see from this long list, this was a reasonably densely inhabited area even then.
After the fall of the Western Roman Empire, the area was gradually disintegrated and Dalmatia was reduced to a smaller region on the northeastern Adriatic coast. Throughout history, the region changed hands many times, but the only conquerors to leave long term impact were Italy and Croatia.
Modern Dalmatia
These days, Dalmatia is the whole southern part of Croatia. It spans the area between the island Pag and mountain Velebit on the north, Croatian border with Bosnia and Herzegovina on the northeast and the bay of Kotor in Montenegro on the south (although the borders are mostly blurry).
The native spelling is Dalmacija. It's pronounced Dahl'ma-tziah.
The coast and the islands are Dalmacija "proper", and the area beyond the mountains that overlook the sea is called Dalmatinska Zagora (za=behind, gora=mountain).
Dalmatians tend to have a strong feeling of belonging to their region. That isn't to say that they are separatist -- in fact, medieval Croat kingdoms were based in Dalmatia, and Dalmatian towns of Nin and Knin were royal capitals, so arguably you can't get more Croat than being from Dalmatia ;-)
Due to its position on the Adriatic coast, and the vicinity of countries in the north, the backbone of Dalmatian economy is tourism. This is despite the fact the roads that lead to Dalmatia are far from perfect, and that there's a relatively scarce amount of sand beaches.
However, due to the way sea currents flow and how the winds blow on the Adriatic, the sea water is much cleaner and much warmer than it is on the Italian side. This, along with the immense number of coves, islands and channels, makes Dalmatia a really attractive place for nautical races, and nautic tourism in general. There's a fair number of marinas there, of course.
Dalmatia also includes several national parks that are tourist attractions in their own right: Paklenica karst river, Kornati archipelago, Krka river rapids and Mljet island within island.
The largest cities in Dalmatia today are evenly distributed along the coast: Zadar, Šibenik, Split, Metković and Dubrovnik. The larger Dalmatian islands are Dugi otok, Ugljan, Pašman, Brač, Hvar, Korčula, Vis, Lastovo and Mljet. The larger Dalmatian mountains are Dinara, Mosor, Kozjak and Biokovo. The rivers are Zrmanja, Krka, Cetina and Neretva.
The Dalmatian dog
A rather distinctive dog breed is called after Dalmatia: the Dalmatian ("Dalmatinac"), whose skin is white with black spots. Its true origin is not certain, as a spotted dog has appeared on imagery since the ancient Egypt, but it is attributed to Dalmatia since Italian and Croatian frescos were found dating back to approximately 1710, depicting the breed. Later works by Thomas Bewick (1792) and Vero Shaw (1882, 1890) established a written standard for the Dalmatians.
The Dalmatian is well-suited for a coach dog, being 50-60 cm tall, well-muscled and enduring. It has a short coat, and the black or liver spots are distributed evenly over its body. But this is topic for another node.