From 9 BC to the end of the 4th century, Pannonia was part of the Roman Empire, located within part of later Hungary's territory.Here, a 600-strong Roman legion created the settlement Aquincum in AD 41–54.
His great-grandson Stephen I ascended the throne in 1000, converting the country to a Christian kingdom.
Applying to Pope Sylvester II, Stephen received the insignia of royalty (including probably a part of the Holy Crown of Hungary, currently kept in the Hungarian Parliament) from the papacy.
By 1006, Stephen had consolidated his power, and started sweeping reforms to convert Hungary into a Western feudal state.
The lesser nobles also began to present Andrew with grievances, a practice that evolved into the institution of the parliament (parlamentum publicum).
In 1241–1242, the kingdom received a major blow with the Mongol (Tatar) Invasion.