In our era, both Ralph Darling and John Elley rose from the ranks to become a general officer. Darling was a Major General in 1813. Beside active service he served on the staff at the Horse Guards. Elley became a Major General in 1819. He commanded the Royal Horse Guards.
An interesting look at a sergeant who was commissioned and served in his regiment is Sergeant Patrick Masterson 87th Foot. He captured an eagle at Barossa. For this feat, he was gazetted an ensign in the York Light Infantry Volunteers. Two months later he was transferred to his former regiment, 87th Foot, without exchange. He remained in it, being promoted lieutenant and captain without purchase. He sold his commission in 1828.