Having It All in the 14th Century : A VISION OF LIGHT <i> by Judith Merkle Riley (Delacorte Press: $19.95; 442 pp.) </i>

If all the chronicles of earthly life were recorded with such drama, flair and wit, the world would be filled with history majors.

This fascinating and factual historical romance, rooted in the real life and hard times of 14th-Century Europe scarred almost beyond recognition by the Black Plague, is a richly brocaded text that illumines this barely civilized but highly charged pre-Renaissance period.

Similar in some ways to Barbara Tuchman’s stately but more academic “A Distant Mirror,� which meticulously delineates that same period but uses instead the life of a nobleman to personalize the record, Judith Merkle Riley in her “A Vision of Light� plucks one imaginary woman from those hazard-strewn days and follows her perilous journey to selfhood. No mean feat for a woman in those days. But Margaret was no ordinary woman.

Margaret of Ashbury, unusual in her struggle to learn--even high-born women were illiterate in medieval times and some even rather proud of it--is an early model of determination coupled with tenderness, the ideal marriage of both her masculine and feminine natures.

From childhood on, Margaret manages to retain her goodness, her faith in God and her grit. Added to these uncommon character traits is her gift for healing, which manifested itself as a light one day in an abandoned church not far from a hut in the forest where she lived with a midwife named Hilde. This encounter occurred while she was recovering from her near death during childbirth. Once well again, thanks to Hilde’s herbs and potions, the two women and Hilde’s idiot but harmless teen-age son embark on a journey that plunges them into perilous adventures and new opportunities to follow their independent natures.

Thanks to her basic intelligence and powers of observation, Margaret is an apt pupil, and in time both of them earn well-deserved good reputations as midwives. Margaret’s gift of healing and her charitable nature produces a loyal following of those who love and admire her. She also generates a following among those who fear and envy her. Notable are bishops in the church, who perceive her gift as a threat to their authority and control and take steps to eliminate her. Her cruel first husband--long thought dead in the plague--turns up to haunt her too.

But Margaret’s healing gift finally brings her to a love-blessed marriage with a much older man who sees nothing at all unusual in her wanting to learn to read and write. With the help of Brother Gregory, an impoverished priest who serves as her scribe, Margaret of Ashbury pours out the story of her dangerous, exciting and variegated life, and we follow her every step of the way.

“A Vision of Light� is a first novel for author Riley, who teaches government studies at Claremont McKenna College and the Claremont Graduate School of California. Most of her research for the book was done at the Huntington Library.