Many old siddurim have a tefillah (prayer) for the Government/President/Emperor etc at the beginning of Shabbos or Yom
Tove Mussaf davening.
It was common for the siddurim to incorporate the name/s of the then present rulers directly into this tefillah.
It is always interesting to see the names and families that were included. Many times these rulers were not particularly
favorable to
the Jews, nevertheless they were included. Seeing those names in print adds a
sense of realism and history to these 100 year old siddurim. I’m sure there are siddurim from far more interesting
locations with unique or
unexpected monarchies in them; but for now this is what I have. Wish I had the time to look up where and when this
minhag originated, would be interesting to know.