Ronan was a Clone drone from the 67th century. He was the consort of General Eve Cicero. When the Tsuranga hospital ship was attacked by a Pting, he and Yasmin Khan were instructed by the Thirteenth Doctor to protect the ship's anti-matter drive.
When Eve died, he and the other passengers recited a special incantation in her memory. (TV: The Tsuranga Conundrum)