It is the photograph that means more to Anwar Sadat's widow than any other. A family portrait taken on the eve of the former Egyptian president's departure to Israel to address the Knesset on November 19 1977. A landmark moment for the Middle East, and for his wife who was convinced she would never see him again.

"I insisted that we took the photos because I was sure he would not come back from the trip," says Dr Jehan Sadat during her first interview since the revolution in Egypt. "I really believed that would be our last photo together as a family. I thought once Anwar got to Israel he would be assassinated by a fanatical Palestinian or a fanatical Jew. I was deeply worried, but didn't show it. I was always very clever about not showing my concern. But as I watched him take off in the helicopter, I was crying. Really crying. It was a very emotional and unforgettable time."

Anwar Sadat returned home safely from that historic trip, only to be assassinated by an Egyptian four years later. The irony is not lost on Jehan who married her husband in 1949, when she was just 15 - "and nine months" - and he was the local hero and defiant revolutionary who was imprisoned for fighting against the British occupation.

"My mother was the one who objected because she thought I was too young to marry," recalls Dr Sadat, who at 76 still looks remarkably youthful. "But Anwar was charming and persuasive - there was never anyone else for me. He was my hero to the end."

Now Dr Sadat, who was in London this week to address the Kabbalah Power of Peace Conference, is lending her support to the revolution in Egypt and is in no doubt that her husband would have joined her. "He would have admired the decision of these well-educated young men and women who organised these protests to create their own democracy," she says, while voicing only fleeting sympathy for deposed President Hosni Mubarak who was not only Anwar Sadat's vice-president, but also shot and wounded while standing beside him on the day of the assassination.

"No one should be in office that long. Thirty years is just too much," she insists. "The future of a country is more important than that of an individual. I did not want to see him hurt, but it was time for new blood and I think the future looks very positive for Egypt."

She is also keen to point out that the Muslim Brotherhood had not been involved in instigating the protests. "They didn't start it and there were no calls from them for the killing of Mubarak. They admitted they were not involved." Perhaps it is the Muslim Brotherhood's alleged lack of involvement that now makes her so confident that the peace accord between Egypt and Israel will be maintained.

"I am absolutely certain that they will respect the treaty - it is far too important," says Dr Sadat, who had a close friendship with the former Israeli President, Ezer Weizman, until his death in 2005. "He and his wife Reuma were our friends and not a single year passed without him calling me on October 6, the day of my husband's death, to say they were thinking of me."

This year marks the 30th anniversary of Anwar Sadat's assassination, though Jehan Sadat says that for her it is no more poignant than previous years, as: "I have never stopped missing him and because of him peace has become the defining theme of my life."

She remembers how shocked she was when her husband first revealed his decision to negotiate peace with Israel. "Like most couples who understand each other we talked about most things, but not everything. He did not for example discuss with me about preparing for war. It was none of my business. But his peace idea came as a shock, and not just to me, but the whole Arab world. But once he made the decision I encouraged him. He wanted the leaders of the other Arab nations to join him. He also told them: 'If you have another plan I will follow you', but they had no plan. He wanted the leaders in Jordan, Syria, Lebanon and Palestine to join him, President Carter and Prime Minister Menachem Begin when they met for initial talks in Giza. He insisted that no one would force them to do anything other than negotiate, but they refused. He just couldn't wait another 30 years to do what was right for his country."

Dr Sadat attributes the effortless recall of this period in her life to the equal measure of pride and fear that she felt at the time. "I was so torn inside because I loved my husband so much, and I was so thrilled when he and Mr Begin won the Nobel Peace Prize, but I was also fearful," she says, twisting her silver, jewelled wristwatch - the last gift her husband gave her before his death. "He was attacked verbally, threatened and called a traitor. We had so many threats. He knew it. We both knew it."

Her voice trails away as she talks of their mutual realisation that her husband would pay a heavy price for making peace with Israel. This huge sacrifice which left her a widow at the age of 46, led to a retreat from public life and the numerous organisations that she founded to help women and children. But Jehan Sadat was always passionate about her teaching at Cairo University, which is where she studied for her masters degree in comparative literature, and it was as an educator and advocate of peace that she returned to keep her husband's memory alive. With the Anwar Sadat Chair for Peace and Development at the University of Maryland, she now divides her year between America and Cairo where her four children, 11 grand-children and eight great-grandchildren live.

Her lecture tours which are dominated by the peace theme made her a natural choice as speaker at the Kabbalah conference, where she shared the platform with Karen Berg, whose husband, Rav Berg founded the organisation in the US. "Karen and I both believe that if you have the power to change yourself, you have the power to change the world," she says. "That was what I thought when I saw men, women and children standing shoulder to shoulder in Tahrir Square. I could see Egypt was entering a new era of advancement to be like other democratic nations. My husband would have been very pleased."