CAMBRIDGE, Mass. — Ruth Simmons says she once wrote the best essay in her literature class only to have one of her Harvard University professors shun her because she was black, or a woman, or both.

More than three decades after that graduate school indignity, Simmons returned to the Harvard campus last week. She is now Brown University's first female president, and represents part of a landmark change going on at the top of the Ivy League.

When Drew Gilpin Faust, the dean of the Radcliffe Institute for Advanced Study, takes over at Harvard on July 1, half of the venerable league's eight schools will be led by women.

Simmons said the four women, including University of Pennsylvania President Amy Gutmann and Princeton President Shirley Tilghman, have carved a path that will grow among the Ivies and beyond.

"When it starts to become the issue of being the last Ivy League school to have a woman president — who wants to do that?" Simmons said at a forum sponsored by Harvard's Radcliffe Institute for Advanced Study. "This is a league and this is a league based on competition."

Also on the panel was Judith Rodin, who became the first woman to lead an Ivy League institution when she became president of Penn in 1994. She is currently president of the Rockefeller Foundation.

Although women have made gains at the top, they still are not proportionately represented in the ranks of tenured faculty at the world's major research universities, the panelists said. Reforms in parental leave and merit-based hiring are needed for women professors to catch up, Tilghman said.

"It is much too early to declare either victory or defeat," Tilghman said. "In a way, the Ivy League is anomalous among research universities in the world."

Gutmann noted the biggest gap in education is between the rich who can afford the ballooning cost of tuition, and the poor who are left outside campus walls.

The presidents each noted their relentless ambition, but at the same time said they wound up at the head of the world's leading universities almost by accident.

What was not an accident, they said, was that Tilghman, Gutmann and Simmons were all young Princeton administrators groomed by former President Harold Shapiro.

"He would deny credit," Gutmann said. "But, he should get credit."