Brettell was born in Rochester, New York.  When he was eight his family moved to Denver, Colorado, and spent his formative years there. He entered Yale University, intent on studying molecular biophysics until hearing professor George Kubler speak, changing his mind to study art history. Brettell received his Bachelor's and Master's, degrees from Yale. At Yale, Brettell met Zoe Caroline Bieler (b. 1950), a graduate student in cultural anthropology, who he married in 1973. He mounted his first art installation, a photography exhibition at Yale, the same year.

One of the first instructors at Wellesley College; first female faculty member at University of Rochester in 1902. Denio was born to John and Celinda (Weatherwax) Denio. She graduated from Mount Holyoke College in 1866. Denio then committed to a brief term as an instructor at Vassar College in Poughkeepsie, New Yrk. Joining Wellesley College in 1876, Denio taught German and Art, classes including, ‘Medieval German Literature,’ In 1883, she created the first inventory of art for the gallery at Wellesley College, the Catalogue of Works of Art Belonging to Wellesley College.