Luciano Spalletti has returned to Roma to replace Rudi Garcia as head coach.
The 56-year-old managed the Giallorossi between 2005 and 2009, guiding the club to the Champions League quarter-finals and twice to Coppa Italia glory, and is now back at the Stadio Olimpico.
Garcia's departure was confirmed on Wednesday after the Frenchman allowed Roma to slip to fifth in the Serie A table on the back of a run of seven games that featured a single victory.
His replacement Spalletti told asroma.it: "I'm emotional because I understand the value of this city, of the club and of the team. I'm enthusiastic to work with such great people."
Spalletti, who is understood to have signed a one-and-a-half-year contract in the Italian capital, joined Zenit St Petersburg after leaving Roma but has been a free agent since March 2014.
He agreed to succeed Garcia on Wednesday after flying to Miami to hold talks with Roma president James Pallotta.
The American businessman said: "We're extremely happy to welcome Luciano Spalletti back to Roma. He's a prizewinning coach who has a long string of successes behind him.
"We can't wait to work together towards bringing Roma back to where we deserve to be."
Spalletti's first assignment will be leading the Giallorossi - currently seven points behind leaders Napoli - against basement boys Hellas Verona in the Eternal City on Sunday.
Roma have managed to reach the last 16 of the Champions League under Garcia's watch and they will face 2014 winners Real Madrid over two legs in February.