When a historical name is trademarked, will the trademark be considered 'weaker' than an invented name?

Question

Like the names of important people of medieval Europe, names of planets of the Solar System and its moons or geographical features etc.

Answer 1

Only slightly less. They would both generally be assessed to have a high distinctiveness.

The use of an existing word or name in connection with goods or services unrelated to any existing meaning is considered an "arbitrary" mark.

• "Saturn" for a vehicle
• "Apple" for electronics

These kinds of marks are generally considered to be less distinctive than wholly "fanciful" or invented names, but still highly distinctive—moreso than suggestive, descriptive, or generic terms.

See generally, Abercrombie & Fitch Co. v. Hunting World, 537 F.2d 4 (2nd Cir. 1976), and Wikipedia's presentation of the distinctiveness scale.