reach back to (some point in time)
1. To originate in and continue on from some previous point or period in time. The traditional ceremony reaches all the way back to the founding of the country. The recipe I'm using reaches back to the days of the settlers.
2. To draw from, contain elements of, or be inspired by some previous period in time or someone or something therefrom. The singer reaches back to the powerhouses of the '70s to delivery some truly funky tunes. Her latest film reaches back to the black-and-white era while creating something wholly original.
reach back (in)to something
to extend back into a particular period in time. This policy reaches back into the last century. Our way of making fine candies reaches back to the recipes used by the founder of the company.