 From the 15th century onwards, all Holy Roman Emperors but one were Austrian archdukes and with the acquisition of the Bohemian and Hungarian crown lands in 1526, the Habsburg hereditary lands became the centre of a major European power.The Archduchy's history as an imperial state ended with the dissolution of the Holy Roman Empire of the German Nation in 1806.It was replaced with the Lower and Upper Austria crown lands of the Austrian Empire.