The push for a synchrotron lightsource in Canada gained impetus in the early 1990s with the formation of the Canadian Institute for Synchrotron Radiation (CISR) with Bancroft as president. In 1994 NSERC recommended building a Canadian synchrotron, and set up a committee to decide between two rival bids to host the facility, led by Dennis Skopik of the University of Saskatchewan and Bancroft of UWO. In 1996 the committee recommend that the Canadian Light Source (CLS) be built in Saskatoon.
With the formation of the Canada Foundation for Innovation a funding mechanism for the lightsource became available, and after what Bancroft has described as a "Herculean" effort by the Saskatchewan team the funding was finalised in 1999. At this point Skopik departed to the US, and Bancroft was appointed as the first director of the CLS. 
Bancrofts appointment ended in 2001,  although he remained as research director until 2004, and he returned to UWO. Bancrofts association with the CLS continues, and he currently serves on their board of directors.