Liverpool manager Brendan Rodgers returned to his former club Swansea to sign Wales midfielder Joe Allen on Friday.
Allen was at Anfield on Thursday to watch Liverpool's 3-0 Europa League win over FC Gomel and the 22-year-old has finally completed his long-awaited move for a transfer fee reported to be around £15 million ($23 million).
Rodgers had been linked with an approach for Allen almost from the moment he was unveiled as Liverpool's new manager in June.
It was believed Swansea had insisted on a clause stopping Rodgers signing any of his old players before they let him move to Merseyside, but the Reds are thought to have made a high enough bid to persuade the south Wales club to let Allen leave.
Speaking after passing his medical on Friday, Allen told Liverpool's website: "I feel incredible. Everyone knows the history of this club, it's a massive club, and I'm delighted to have joined.
"The passion that people here have for football is something I share and I want to be part of that.
"I'm looking forward to being part of some great years ahead for Liverpool."
Rodgers has tremendous faith in Allen after helping him develop at Swansea and he believes his style of intelligent style of play will be key to Liverpool's evolution.
"I'm absolutely delighted Joe has made the decision to come with us on this journey," Rodger said.
"He is a player whose profile will fit perfectly with the ideas of this group.
"His ability to control and dominate the ball is an important ingredient in our attempt to gain success on the field.
"Joe has had a fantastic education at Swansea and will now begin the next chapter in his exciting career, and I wish him all the very best in what I'm sure will be a long and distinguished career here at Liverpool."