Winnie Madikizela-Mandela's legacy will be preserved at Constitution Hill in a permanent photographic exhibition that was officially opened on Thursday.This was revealed by Constitution Hill's Reuben Phasha, who spoke at a memorial service held for struggle icon Winnie Madikizela-Mandela earlier on Monday.Madikizela-Mandela died on April 2 at the age of 81.Her life was celebrated by several politicians and family members at Constitution Hill on Monday morning.Minister of Energy Jeff Radebe spoke at the service and said that the Mother of the Nation played a significant role in his life."There are occasions where my family and I have sought her guidance and wisdom to traverse many of the challenges of our lives," he said.READ: Free State ANC defends Magashule after Manuel's Madikizela-Mandela Brandfort home attackRadebe said Madikizela-Mandela was never afraid to speak truth to power."She never wavered to state her mind in correcting the wrongs and reprimanding the wayward," he said."Today, we are reuniting the two icons (Nelson Mandela and Winnie) who were larger than life in heavenly matrimony. It is like we are saying as they were powerful forces in the world, in this temporary world, they are now being joined as equally powerful forces in the world yonder," Radebe said."As Mandela once quipped, we can be assured that the ANC branch in heaven is growing, and its leadership is being strengthened by the arrival of Mam' Winnie."Radebe said much needed to be done to celebrate Madikizela-Mandela's life and for Radebe said much needed to be done to celebrate Madikizela-Mandela's life and for her legacy as a struggle hero to be remembered."Weak leadership survives on short-term populism. I found our icon, Nelson Mandela, Mama Winnie, and the [Nelson Mandela] Foundation, though popular in their own right, avoiding populism as a tool of mobilising," he said.Former minister of finance Trevor Manuel also spoke."One of the things I learned from Mam' Winnie is that unity is forged in struggle. If you don't wage struggle, you can neither see unity nor will you find it," Manuel said.