The Goths were a German people. They originated in Scandinavia, but by the 2nd century of the Christian Era had moved into what is now Southern Russia. The Goths had adopted the habit of fighting on horseback. This arose from the fact that the first area the Goths invaded in the 2nd century AD were the vast plains of Eastern Europe and southern Russia. This was horse country and Goths quickly took to mounted warfare. This was aided by the fact that the stirrup was just being introduced into Europe and, more importantly, because the Goths considered warfare the ultimate experience, preferable to any other undertaking. Doing it on horseback was a lot more efficient. With horses, they could wage war faster and farther than they ever had in the past. While the Goths had speed, they did not have mass. They became like nomads, always on the move.
There were actually two groups of Goths, the Visigoths (meaning the "West Goths") and the Ostrogoths (the "East Goths"). The Goths first burst upon the scene of history in the 3rd Century, when they swarmed out of Southern Russia by both land and sea to beset the Roman Empire. After an heroic struggle, the Romans managed to drive them back to work on their military techniques a little more. In the mid-4th century the Goths were attacked by even wilder peoples, like the Huns The Visigoths sought security within the boundries of the Roman Empire, offering to help defend the Balkans in return for land, but the Emperor Valens spurned their offer. So they invaded, and in 378 overwhelmed a Roman army at Adrianople, using cavalry in combination with a fortified camp. The victory seems to have surprised the Visigoths almost as much as it did the Romans, for they agreed to settle in the Balkans and help defend them against other tribes. Within a century, the Visigoths had drifted westwards, to settle in southern Gaul (modern France) and Spain, where they set up a kingdom of their own.
Meanwhile, the Ostrogoths found themselves subjects of the Huns, and participated in the Hunnish invasions of Europe during the first half of the 5th century, fighting under Attila against their Visigothic cousins and the Romans at the great battle of Chalons in 451. The Huns and their allies lost this battle and thus began their rapid decline. With the collapse of the Hunnish empire, the Ostrogoths for a time settled in the Balkans, where they were more or less subject to the authority of the Eastern Roman Emperor. In 493 the Emperor "authorized" the Ostrogoths to occupy Italy, which was then under the control of still other Germanic babarians. Under their able king Theoderic, the Goths accomplished this in surprisingly short order, and established a kingdom of their own. This came to grief in the mid 6th century, when the Eastern Roman Emperor Justinian decided to reestablish Imperial control over Italy: The war lasted over 20 years and brought absolute ruination to Italy. Thus did the Ostrogoths exit the scene.
The Visigothic kingdom in Spain (the Franks drove them out of most of France in the 6th century), proved a vigorous one. A more or less stable government was established, the province was rich, and Roman institutions remained pretty much intact. The knigdom flourished, producing such worthies as St. Isidore of Seville. But in 711 the Islamic warrior chief Taric led a raid across the Straits of Hercules (now the Straits of Gibraltar). This came at a time when there considerable disorder in Visigothic Spain, a civil war just then being in progress. The raid was reinforced, and within just a few years Visigothic Spain was no more, submerged beneath an Islamic tide. However, Roman and Visigothic fugitives established small states in the mountains of northern Spain, which became the nuclei from which the reconquista was undertaken.
The Goths left a considerable heritage. Perhaps their most lasting influence was linguistic, for both Italian and Spanish are strongly influenced by Gothic words, one of the reasons that the two diverge so greatly from French.