How many letters does the top answer for “wrote the blue castle” have?

The most common answer is montgomery (10 letters).

Crossword clue: wrote the blue castle

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

montgomery 10 letters wd-fact-v3

the state capital of Alabama on the Mobile River

wrote blue 67% similar → mitchell

wrote the castle 67% similar → kafka

author of the blue castle 50% similar → montgomery

wrote blue dragon 50% similar → toriyama

wrote blue velvet 50% similar → hopper, lynch

wrote takeshi's castle 50% similar → kitano

wrote the blue bird 50% similar → daulnoy, maeterlinck

wrote the interior castle 50% similar → avila