The first inhabitants of the Czech lands were prehistoric fish. The country, at the time, was covered by an ocean - thanks to which, it is possible to find fossils of Trilobites in the Czech Republic today. The land left behind the receding sea, was populated by dinosaurs and later by Neanderthals. The ancient settlement of the present day Czech Republic by people, culminated in the fourth century B.C. with the arrival of the Celts, the first modern human inhabitants of this territory that we know of.

The next peoples to inhabit the area were the Germanic Marcomanni and Quadi tribes from the West. Later, the Slavic peoples settled into the regions in the sixth and seventh centuries. At some time during the ninth century, Greater Moravia, as the region was then known, was ruled by the Moravian Prince Svatopluk. This was the first legal sort of state structure in the area to accept Christianity and the cultural development of the Greater Moravian Empire is inseparably linked to the spread of the Eastern Byzantine liturgy of Sts Cyril and Methodius who came to these parts in 863 AD.

The Greater Moravian Empire, which by this time had grown to include today's South Moravia, the southernmost bits of present-day Poland and Silesia, the western part of Hungary and for a short time, the whole of Bohemia disintegrated thanks to the Hungarian invasion of 903 or 904 AD and political intrigue in the early days of the Holy Roman Empire. After that, the Slavic Mission in Moravia, having been established by the missionaries Cyril and Methodius collapsed and the population reverted to tribal conditions.