In the early decades of the 1900s, two institutions were founded: Canberra, the nation's capital; and within it a girls' school, opened by the Community of the Sisters of the Church, led by Sister Hilda, in a borrowed rectory with ten students and a steadfast belief in the impact of education for women.

For a century, Canberra and its Girls Grammar School have grown in step – through economic depression, war and bushfire, through the postwar boom that transformed a small administrative town into a vibrant capital, and through decades of expansion, reinvention and ambition. As Canberra transformed, so did CGGS, emerging from each challenge with deepened purpose. For a century its classrooms have shaped dreamers, doers and disrupters, women who have carried the School's founding spirit out to every corner of the globe.

A Mantle of Light is the story of the first 100 years of CGGS: the visionaries who built it, the communities who sustained it and the generations of Grammarians who grew up within its walls. At its heart, this is a story about what becomes possible when girls are given the freedom to flourish.