The Norman conquest of Southern Italy began in the 11th century when Norman adventurers, originally mercenaries, arrived in the region. They sought land and power, gradually conquering territories from the Byzantine Empire and local rulers. Key figures like Robert Guiscard played significant roles in establishing Norman control over areas such as Apulia and Calabria. By the late 11th century, the Normans had unified much of Southern Italy under their rule, leading to the establishment of the Kingdom of Sicily. This conquest significantly influenced the culture, politics, and economy of the region, blending Norman, Italian, and Arab elements into a unique society.