Along with the several damselflies by the river at Stratford, there were two dragonflies, of different species. One was large, brown, and constantly on the move. It stayed too far out over the water to get a clear view, or any sort of picture. The other was more cooperative, spending time resting on a leaf. It was a broad bodied chaser, which is indeed one of the commoner dragonflies.
It was a mature male. Immature males and all females are yellow-brown.