Fidel, 67, appeared smiling and in good health as he mingled with his erstwhile opponents and showered them with cocktails and canapes. He spent several hours shaking hands with them, showed a sharp memory for people and details, asked questions and signed autographs - in some cases on American passports.
The joviality marks a softening on both sides. One guest, Luis Tornes, 70, a veteran of the failed Bay of Pigs invasion in 1961, was asked what he would have done if he had come face to face with Castro 20 years ago. 'Why don't you ask what he would have done 20 years ago? He would have killed me.'
Now, however, Fidel is eager to encourage the people he used to scorn as gusanos (worms) to invest in their old homeland, bringing desperately needed dollars to joint ventures in tourism and industry.
Striking a more serious note, the mayor of Seville, Alejandro Rojas-Marcos, cancelled yesterday's 'hangover Monday', a holiday which follows six days of drinking and dancing in the annual spring fair. 'The fiesta's got to end sometime. Anyway I don't like the name 'hangover Monday' at all. It gives the impression that we don't know how to hold our drink, which is quite untrue,' he said.
But it is not easy to dispel the city's partying image and residents are grumbling, even though they will get their day off on another day. 'It's a day for people to rest their feet, throat and hands after a week's dancing, singing and clapping,' a local schoolteacher said. Another lamented that while they could ban hangover Monday, 'they couldn't ban the hangover'.
The legendary Spanish bullfighter, Manuel Benitez 'El Cordobes', is to return to the professional bullring after 13 years. 'In fact I have never retired. I will die as a bullfighter,' said Benitez, who is 58 next week.
He has signed a contract for four corridas for a fee of 400m pesetas ( pounds 1.9m). His once lustrous hair is now thinning, but he looks fit and says he is ready to face the bulls again. His first appearance is expected in Tarragona on 21 May.
Also planning a comeback is Italy's former foreign minister, Gianni De Michelis, who is trying to to recycle himself as a chemistry professor. He is finding it trickier than he thought. Students are complaining that he has been out of the lecture theatre for too long - 19 years - and that he is linked with political corruption.
'A professor must possess at least two requisites: namely a deep understanding of the material and moral correctness,' said a student document sent to university administrators who are considering De Michelis' application. But De Michelis, who quit politics in 1992 and has been implicated in a number of corruption cases, says that becoming a professor is the only way he can make a living.