Complex sentence: In 1859, Venetia became a part of the Austrian Empire, when Lombardy went to the Kingdom of Italy; in 1866, Venetia too joined the Kingdom of Italy, and then followed its history.
Split into simpler sentences: In 1859, Venetia became a part of the Austrian Empire, when Lombardy went to the Kingdom of Italy. In 1866, also Venetia was unified to the Kingdom of Italy, and then followed its history.