Which artist is recognized as the leading painter of "grand manner portraiture"?

There are two artists that are generally recognized as the forefathers of the aesthetic known as "grand manner portraiture". These two figures are Peter Paul Rubens and Anthony van Dyck. The work that they set forth inspired a series of other artists throughout the 18th, 19th, and 20th centuries.

I believe the answer is Sir Joshua Reynolds

Sir Joshua Reynolds was a painter that lived between the period of 1723-1792.

The main subjects for his painting were mainly heroices people and nobles. It is predicted that in the course of his life, he produced at least 3,000 potraits of nobles/heroic people.