Slaves were used in Greece, especially so at Athens, where, at the height of the city's power, there were four times as many slaves as citizens. The slaves took a prominent part in the domestic and public economy, being used as agricultural laborers, and as artificers and servants, and by the State as policemen and soldiers. Sparta possessed very few slaves, probably only enough to supply the demand for domestic servants. With the rapid progress of the Greeks came an increased use of slaves, and the wars not being sufficient to supply the demand, an open slave trade was soon established. In Greece arose to its height that peculiar form of slavery practiced by the early Hebrews, wherein foreigners violating laws, and Greeks themselves, if unable to meet their debts, were sold with their families into slavery. This brought about such a threatening state of affairs that by the wise laws of Solon this form of slavery was abolished. This peculiar slavery also existed in the early days of Rome, but in the third century before Christ it was also abolished. In the Roman Empire slavery existed from the earliest times, and was carried to an excess not known before or since in the history of slavery. The wonderful and rapid rise of the Romans in power, domain and wealth led to a moral and political degeneracy which demanded the increased use of slaves in all branches of domestic and public life. Here, as in Greece, the Wars of Conquest bringing in, as they did, vast numbers of slaves, failed to supply the demand, and here again, as in Greece, the slave trade, with its acts of piracy, was established to obtain a supply, and the occupation of the professional slave hunter and slave dealer became fully recognized and were the forerunners of similar acts in the history of Negro slavery many centuries later. The abuses brought on by the Roman system of slavery led to such decay and corruption in the Empire that it became an easy prize for the Teutonic tribes, and Rome of the West fell to rise no more, about the middle of the fifth century. Then probably began the Feudal system, which practically abolished the ancient form of slavery, and in its place the lower classes of the population were put in the semi-servile condition of serfs and villeins to their Feudal Lords. This system spread in Germany, France, England and Russia, but by the time of the capture of Constantinople in 1453 by the Turks, Feudalism, the last relic of slavery in Western Europe, was almost extinct, and was gradually assuming a very mild form in the other countries, when suddenly and unexpectedly slavery was revived and perpetuated in a new, its modern form, by a singular and interesting series of events which brought about the ruthless bondage of an entire people to nations whom they had never offended.