In 1609 he succeeded his father as Grand Duke of Tuscany but, on 19 October 1608 in Florence, he increased the family's reputation for lavish entertainments when marrying Archduchess Magdalena of Austria, sister of the Emperor Ferdinand II. These were so spectacular a display on the river Arno that observers claimed nothing like it had been seen ever before. The stage was the whole stretch of river between the Ponte alla Carraia and the Ponte Santa Trinita embellished with statues for the occasion. The audience, sitting in immense
grandstands erected on the Lugarni, were treated to a performance by gigantic artificially constructed dolphins, lobsters and fire-spitting hydra, sailed round an artificial island, captured the Golden Fleece. Finally, the Archduchess was presented with six red apples symbolic of the Medicean 'palle'.

Cosimo II also shared his father's taste for building. He extended the Palazzo Pitti and reconstructed yet another villa for his family, the villa of Poggio Imperiale near Arcetri. Here he set up a telescope which Galileo Galilei had brought with him to Florence and where Galileo himself was offered sanctuary. On 28 February 1621 in Florence, Cosimo II died, aged only thirty, having achieved very little worthy of recording.
 

"The Rise and Fall of The House of Medici", by Christopher Hibbert