it was at a british mathematical colloquium (todd attended the colloquium for each one of its first 25 years) where todd talked on mathieu groups, a subject to which he made considerable contributions.

How would the previous sentence be correctly capitalized?
It was at a British Mathematical Colloquium (Todd attended the Colloquium for each one of its first 25 years) where Todd talked on Mathieu groups, a subject to which he made considerable contributions.