A crowd of hundreds filled the main hall and an overflow room, and yet more people gathered in the first and second floor galleries of the STUC Centre to hear and be inspired by the remarkable Aleida Guevara, speaking about Cuba and her father Che.
Aleida was in Glasgow on a British visit, campaigning to win justice for the Miami Five and to end the illegal US blockade.
"Most of you will know the essential story of the Cuban revolution and the strides we have made since then," she said.
"But sometimes you might take your eyes off the situation.
"Living the blockade is a real struggle, every day."
Cubans had suffered 500 years of oppression and then 50 years of blockade, she said, but the most painful problem was the lack of vital foodstuffs and medicines.
Appealing for justice for the Miami Five political prisoners held in the US, Aleida added: "We are not asking the USA to do anything special, just to follow their own laws.
"If they did that, the five would be back in Cuba tomorrow."
Dr Guevara, a paediatrician, said Cuba was training doctors for other poor countries and drew some hard practical lessons for supporters in Britain and the developed world.
"Solidarity is sharing what you can see other people need," she said.
"Not sharing what you already have too much of.
"It boils down to something very simple - we have to work together.
"There's a lot of talk about support for us, but we need action.
"You might be worried about us, but we are very worried about you too," Aleida quipped.
"You worked for many years get free public services like education and health - and now you're allowing them to privatise it all!"