How many letters does the top answer for “the title of two historical books in the old testament.” have?

The most common answer is king (4 letters).

Crossword clue: the title of two historical books in the old testament.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

king 4 letters web-def

a male sovereign; ruler of a kingdom