Pro of Jemestir
The alias used by Tristan on his first visit to Ireland.
He was ill from poison, and had washed up on the Irish shore. Knowing that Ireland was at war with Cornwall, he concealed his identity and represented himself as Pro of Jemestir. “Pro” was cured of his poison by the medicines of Isolde, and he was appointed by the King of Ireland to travel to Britain and obtain food to ameliorate a famine.
On his second visit, he used the name Tantrist.
Source
Tristrant | Eilhart von Oberge, 1170–1190