This will be an expository talk, at least for the most part. I will try to explain, in a way that should be accessible to Master\'s students of Mathematics, the approach, dating from the late 1970s, that Lakshmibai and Seshadri took to solve problems of invariant theory. It is based on Standard Monomial Theory that was then recently developed by them along with Musili (building on the work of Hodge). The ideas involved have since been developed, expanded, combined, clarified, etc. in manifold ways. The talk is dedicated to the memory of Prof. V. Lakshmibai who passed away in December 2023 and for whom a memorial conference is being held at ICTS in November 2025.
