Arsenal have secured the services of Lucas Perez, the striker joining from Deportivo La Coruna.
Manager Arsene Wenger confirmed on Saturday that the 27-year-old, along with Valencia defender Shkodran Mustafi, had agreed terms, with the official confirmation on Tuesday.
The Premier League club have not revealed any details surrounding the fee - believed to be in the region of £17million - or the length of the deal.
"He's not only a goalscorer, he's a guy who combines well with partners, who can give a final ball and makes good runs," Wenger told Arsenals' official website.
"He's got a good eye for goal and had an outstanding season last year."
Wenger had come under pressure for a perceived lack of activity in the transfer market, with Gunners fans getting restless having gone without a Premier League title since 2004.
Perez plied his trade for several clubs across Europe, including Rayo Vallecano, Karpaty Lviv and PAOK, before joining Deportivo, initially on loan, in 2014.
The 27-year-old, renowned for his pace and work rate, scored 17 goals in 36 league appearances for the club last season, while also providing 10 assists.