Adam Lallana has completed his £25m move from Southampton to Liverpool.
Lallana, 26, is manager Brendan Rodgers's second signing of the summer and joins former team-mate Rickie Lambert at Anfield on a long-term deal.
The midfielder, who played for England during the 2014 World Cup in Brazil, made 265 appearances for Saints.
"I am so excited for the next chapter of my career, coming to a special club like Liverpool," said Lallana, who passed a medical at the weekend.
"Hopefully I can settle in quickly and I will give it my best throughout the whole time I'm here.
"I hope I can add something to the team and hopefully we can win trophies. That's why I'm here - for success."
The Reds have also agreed a deal to sign Bayer Leverkusen's Germany Under-21 midfielder Emre Can for a fee of about £10m.
Lallana, who will wear the number 20 shirt at Liverpool, earned a place on the PFA's Premier League team of the year for his performances last season, when he was ever-present for Saints, scoring nine goals.
Bournemouth, whom he left to join Southampton as a 12-year-old, will receive a percentage of the fee because they negotiated a sell-on clause written into Lallana's contract.
With Luke Shaw also leaving in a £27m transfer to Manchester United, it has been a summer of change at Saints, who appointed Ronald Koeman as their new manager in June following Mauricio Pochettino's move to Tottenham.
Southampton say the income received from Lallana's transfer will be reinvested in the squad.
Liverpool open their Premier League campaign against Southampton at Anfield on 16 August.
"It's fate," said Lallana. "Rickie Lambert and I spoke about it and he said he could have bet his mortgage on it."
Lallana intends to take a couple of weeks off following what he admitted was a disappointing World Cup campaign in which England failed to qualify from the group stages.
He is relishing the chance to play Champions League football for the first time.
"Everyone is telling me that the atmosphere on Tuesday and Wednesday evenings at Anfield is something special," said Lallana, who was made Southampton captain in 2012.
"To think, five or six years ago, I was playing in League One."