Everton have signed Belgium international Amadou Onana from Lille for an undisclosed fee, understood to be up to £34million, agreeing a five-year contract.
The 20-year-old central midfielder, considered one of Europe's most exciting talents, was poised to join West Ham until Everton stepped in to match their offer last week.
Onana was in the stands to watch Everton's opening game against Chelsea and becomes their fifth signing of the summer following the arrivals of defenders James Tarkowski, Ruben Vinagre and Conor Coady and forward Dwight McNeil.
Powerful, fast, technically skilled and with the ability to be used in a range of central-midfield roles, Onana revealed the chance to play for manager Frank Lampard, passionate fans and 'one of the biggest clubs in England' were key to him committing his long-term future to Everton.