Nelson Mandela is an archetypical engagement leader. After 27 brutal years in prison, he emerged as a fervent advocate of engaging with the very people and institutions that oppressed him and others in South Africa's movement for democracy. When he was released in 1990, he spent the next four years in negotiation with the stalwarts of the apartheid regime. As President, he continued to ensure that all faces and voices of his country were represented in government, business and other institutions. Mandela helped people of disparate cultures, even some of whom had a history of violent enmity, to see that only by actively engaging with "the enemy" (something most had previously been unwilling to do) could any of them achieve their ambitious goals.
We can learn much about engagement leadership from President Mandela, but it would be defeatist to think that one must be an extraordinary person like Mandela to be a successful engagement leader. Leaders are, at heart, ordinary people who are willing and able to stretch themselves and others to achieve extraordinary outcomes.