It all began with the aurochs.

http://en.wikipedia.org/wiki/Aurochs

The aurochs or urus (Bos primigenius) was a very large type of cattle that was prevalent in Europe until its extinction in 1627.

Aurochs are depicted in many Paleolithic European cave paintings such as those found at Lascaux and Livernon in France. Early carvings of the aurochs have also been found. The impressive and dangerous aurochs survived into the Iron Age in Anatolia and the Near East, and was worshipped throughout that area as a sacred animal, the Lunar Bull, associated with the Great Goddess and later with Mithras.

Aurochs had several features rarely seen in modern cattle, such as lyre-shaped horns set at a forward angle, a pale stripe down the spine, and sexual dimorphism of coat color. Males were black with a pale eel stripe or finching down the spine, while females and calves were reddish. Aurochs were also known to have very aggressive temperaments and killing one was seen as a great act of courage in ancient cultures. The size of the ancient aurochs was far larger than most modern cattle, approximately 2 metres (6.5 feet) at the shoulder, and weighing 1,000 kilograms (2,200 lbs).

According to the Paleontologisk Museum, University of Oslo, aurochs evolved in India some two million years ago, migrated into the Middle East and further into Asia, and reached Europe about 250,000 years ago.[10] They were once considered a distinct species from modern European cattle (Bos taurus), but more recent taxonomy has rejected this distinction. The South Asian domestic cattle, or zebu, descended from a different group of aurochs at the edge of the Thar Desert in India; this would explain zebu resistance to drought.

Domestication of the aurochs began in the southern Caucasus and northern Mesopotamia from about the 6th millennium BC, while genetic evidence suggests that aurochs were independently domesticated in northern Africa and in India.

The last recorded live aurochs, a female, died in 1627 in the Jaktorów Forest, Poland. The skull was later taken by the Swedish Army during the Swedish invasion of Poland (1655–1660) and is now the property of Livrustkammaren in Stockholm.

In the 1920s two German zoo directors, the brothers Heinz and Lutz Heck, attempted to breed the aurochs "back into existence" from the domestic cattle that were their descendants. Their plan was based on the concept that a species is not extinct as long as all its genes are still present in a living population. The result is the modern breed called Heck cattle, which bears an incomplete resemblance to the physiology of the wild aurochs.