Cal Gothic Bastard  Suggested by donshottype 
Rotunda Pommerania  Suggested by donshottype 
Cal Carolingian Gothic  Suggested by lllllll 

Looks like calligraphy with a broad nib using lower case letters in the general style of Rotunda, Rundgotish or Italian Gothic. Some of the letters in Rotunda Pommerania, such as _e_ and _o_ are an approximate match while others are different.

The _D_ and _R_ are also calligraphy with a broad nib and are similar to style of of the Gothic Bastarda.
Calligrapher Gothic Bastard is an approximate match but the top rhs of _R_ is a broken stroke rather than a smooth loop.
Note that this suggestion was first made by Heron2001 https://www.dafont.com/forum/read/342573/deus-salve-o-rei

A modern calligrapher has produced a poster in a similar style to the titling for Deus salve o Rei, which is available for for purchase as a print:
https://hyvyys.deviantart.com/art/Bastard-Secretary-494785926