(CNN) -- For nearly 30 years, one man has dominated Egypt. Hosni Mubarak, 82, has survived would-be assassins and ill health, crushed a rising Islamist radical movement and maintained the peace with neighboring Israel that got his predecessor killed. His government's continued observance of the Camp David accords with Israel is the cornerstone of what peace has been achieved in the decades-long Arab-Israeli conflict. Following the revolt that toppled Tunisia's longtime strongman, demonstrators in the streets of Cairo are standing up to riot police and chanting, "Mubarak, Saudi Arabia is waiting for you." Experienced observers say it's the most most significant challenge to his rule yet.
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Hosni Mubarak has held power since 1981
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A 30-year state of emergency has aided his rule
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He now faces widespread demonstrations after Tunisia's revolt
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The uprising removed the "barrier of fear," one analyst says
"I think what the events in @placeholder did was take that sense that nothing could ever change and lead a few people to question it," he said.