Italian police say two members of the Red Brigades guerrilla group have been detained in a joint operation in Egypt.
Algranati and Falessi have both been convicted in their absence
One is Rita Algranati, 46, who was convicted in her absence of the kidnap and murder of former Italian prime minister Aldo Moro in 1978.
The other is Maurizio Falessi, 50, who has a conviction for attempted murder of a politician and other crimes.
Police say the two were arrested at Cairo airport as they tried to board a flight using false identification.
They were immediately flown to Rome.
The Red Brigades is a far-left militant group blamed for a series of attacks in Italy in the 1970s and 1980s.
Italian Interior Minister Giuseppe Pisanu welcomed the arrests.
"Twenty years after they went on the run, the state has brought to justice two terrorists whose actions bloodied Italy during the 'Years of Lead' (years of political violence'," he said.
"Those who, still today, mean to commit political violence, know that sooner or later they will be found by the patient forces of the state and of the law."
The Red Brigades claimed responsibility for kidnapping Mr Moro, then head of the Christian Democratic party, in 1978.
He was abducted in a street in Rome and four of his bodyguards were killed in the kidnapping.
Mr Moro was held for 55 days before he was killed and his body dumped in the boot of a car near the headquarters of the Christian Democrats and Communist parties in Rome.
Algranati is also believed to have been an accomplice in three other political murders and is considered a key figure in the Red Brigades group.
She is married to Alessio Casimirri, who is also wanted by police in connection with Mr Moro's murder. Police believe he is in hiding in Nicaragua.
The arrests are the latest success against the Red Brigades.
In December, Italian police uncovered an arms and ammunition cache they believed belonged to the group, only a few months after arresting nine suspected members in October.