The Swiss international, who appeared in all four of his nation's matches at the World Cup this summer and has been capped a total of 52 times by his country, becomes the northern Germany side's second major signing this summer after Pierre-Michel Lasogga.
'Delighted to be here'
"I already feel really good and I'm delighted to be here," Behrami said on his new club's website. "Hamburg is a new experience for me and they are a great club. This is a very important moment of my career."
The 29-year-old requested a move from Napoli this summer after failing to break into their first team on a more regular basis. The former CFC Genoa, Hellas Verona, SS Lazio, West Ham United FC and ACF Fiorentina midfielder prefers a more defensive role to the one he was given at the Italian club last season. "I think that's where my strength lies - in the tackle, and tactically," he said.
His value can be read into the words of Napoli's president Aurelio De Laurentiis. "Valon always honoured the shirt he wore and gave a great deal to Napoli," he said. "I would like to thank him for his great sacrifice, great professionalism and for being a true warrior."
Those are just some of the qualities Hamburg can now look forward to with Behrami already training with his new team-mates in preparation for his Bundesliga debut, having previously played in Swiss, English and Italian football.