Irish rock band U2 will receive one of Portugal's highest honours before giving a concert in Lisbon on Sunday.
U2 are currently on the European leg of their world tour
President Jorge Sampaio will present the Order of Liberty to the veteran four-piece in recognition of their humanitarian efforts.
"Over the past 25 years the band has allied its public exposure to the defence of human rights," said a presidential spokeswoman.
Sunday's concert marks the end of the European leg of U2's world tour.
According to the president's office, the Order of Liberty honours efforts "to defend civilised values, dignify mankind and the cause of liberty".
It praised the band's campaigning for Third World debt relief, most recently in last month's Live 8 concert in Hyde Park.
U2 opened the event by singing Sgt Pepper's Lonely Hearts Club Band with Sir Paul McCartney.
All four members of the group - Bono, The Edge, Adam Clayton and Larry Mullen - are expected to attend the investiture ceremony.
U2 will conclude their world tour in the United States in December.