Root, ending and realm type
Every name has three layers. The root says what the land is about. The ending says what kind of place it is. The realm type says who rules it. Eisen is German for iron, and -mark means a borderland, so Eisenmark is an iron frontier. The card can show it as Grand Duchy of Eisenmark.
German, Old Norse and Old English roots, such as Schnee (snow), Wald (forest) or Frost, join with an ending like -heim (home), -burg (walled town) or -gard (protected stronghold). Latin and Greek roots, such as Solaria (from sol, the sun) or Thalassia (from thalassa, the sea), already look like finished country names. They stand alone.
Choose the realm type with care
The type tells readers who sits on the throne. An Empire has an emperor or empress over many lands. A Kingdom has a king or queen. A Grand Duchy is led by a grand duke or duchess and ranks just below a king. A Margraviate is led by a margrave, a military governor of a dangerous borderland. The word comes from Markgraf, where Mark means border.
Let the ending and the type agree. Margraviate of Eisenmark says "border" twice, which suits a fortress state. Types such as Emirate, Sultanate, Caliphate and Tsardom belong to specific real cultures. A Germanic root next to one of them can confuse readers, so use them only when your world has a matching people.
Say it before you commit
Short roots like Is, Run or Ash can hide inside longer words, so read the full name aloud. Each card has a Say it respelling, for example Eisen as EYE-zen. Open Details for the parts. If the realm will host a school, take the name to the magic academy generator. Rulers need titles too: see noble titles.