Ric Dice here. We do not have the strong "S" in English, so it is spelled THEISS. That is the way my 8th Grandfather, Johann Matthias Theiss spelled the name. He came to the US in 1730. He was the gr grandson of Thomas THEISS/THEIS of Ruthweiler, near Lichtenberg in the Rhineland Pfalz. I am trying to connect THEISS/THEIS from the late 1500s to the early 1800s in and around Kusel. Thonas Theiss b bef 1605 d 1 Sept 1675 was a censor in Ruthweiler. He had 2 at least 2 wies and a large family. Where are you from?