By the Pragmatic Sanction of 1549, Charles V declared the Seventeen Provinces a united and indivisible Habsburg dominion. Between 1555 and 1556, the House of Habsburg split into an Austro-German and a Spanish branch as a consequence of Charles' "abdications of Brussels". The Netherlands were left to of his son Philip II of Spain, while his brother Archduke Ferdinand I succeeded him as Holy Roman Emperor. The Seventeen Provinces, "de jure" still fiefs of the Holy Roman Empire, from that time on "de facto" were ruled by the Spanish branch of the Habsburgs as part of the Burgundian heritage.