Fernando Santos, who was coach of the Portuguese national team until last month, was appointed as Poland’s new coach on Tuesday.
“From today I am Polish,” Santos declared at the official ceremony in Warsaw.
“It is an honor to continue my work as a coach here,” he added.
Santos, 68, succeeds Czeslaw Michniewicz, who was sacked last month following a round of 16 appearance at the World Cup in Qatar.
Poland finished second in their group, beating Saudi Arabia, drawing with Mexico, and losing to eventual champions Argentina.
In the round of 16 for the first time in 36 years, they were knocked out after a tame 3-1 defeat at the hands of eventual runners-up France.
The Lisbon-born Santos resigned as Portugal coach in December following the team’s upset World Cup quarterfinal loss to Morocco.
Appointed Portugal’s coach in September 2014, Santos won the country’s first major title at Euro 2016 and followed it up with the 2019 Nations League.
However, his time in charge also saw round of 16 exits at the 2018 World Cup and Euro 2020.
“The choice was difficult, but we chose the best,” said Cezary Kulesza, president of the Polish football federation.
“Our first objective is to qualify for the Eurocup” which will take place in Germany in 2024, he added.
Santos also coached the Greece national team between 2010 and 2014.