Complex sentence: In 1803, Napoleon raised the duchy to the Electorate of Württemberg of the Holy Roman Empire however soon afterward when he abolished the Empire in 1806, the Electorate was elevated to the Kingdom of Württemberg.
Split into simpler sentences: In 1803, Napoleon raised the duchy to the Electorate of Württemberg of the Holy Roman Empire. However, soon afterward, (when he abolished the Empire in 1806), the Electorate was elevated to the Kingdom of Württemberg.