Former Chelsea manager Claudio Ranieri has become head coach of Inter Milan on a contract running until June 2013.
The announcement followed swiftly on Gian Piero Gasperini's sacking on Wednesday morning.
Gasperini was relieved of his duties after four defeats and a draw in his five matches in charge, having only succeeded Leonardo in June.
It will be Ranieri's first job since quitting Roma in February following a run of four straight defeats.
"Claudio Ranieri is officially the new coach of Inter," read an official club statement on Thursday.
"All of Inter has the pleasure of welcoming Claudio Ranieri and his staff. He will guide today's training session and will be unveiled tomorrow to the press."
Under Gasperini, Inter lost 3-1 against newly-promoted Novara on Tuesday night and suffered defeats to Palermo in Serie A, Trabzonspor in the Champions League, and to city rivals AC Milan in the Italian Super Cup.
The only game of Gasperini's tenure that did not end in defeat was a 0-0 draw at home to Roma last weekend.
But former Juventus boss Ranieri has also struggled in the past to win silverware, with his only trophies an Italian Cup in 1996 with Fiorentina and a Spanish Cup with Valencia three years later.
In his first season with Roma, he almost took them to the Serie A title before they were pipped by Jose Mourinho's Inter side.
Last season his team struggled, however, and Ranieri resigned with his team facing elimination from the Champions League and dropping out of contention for European qualifying places in the league.
CLAUDIO RANIERI'S MANAGERIAL CAREER
1987-1988 Campania Puteolana
1988-1991 Cagliari
1991-1993 Napoli
1993-1997 Fiorentina
1997-1999 Valencia
1999-2000 Atletico Madrid
2000-2004 Chelsea
2004-2005 Valencia
2007 Parma
2007-2009 Juventus
2009-2011 Roma
2011 Inter