How many letters does the top answer for “wrote father brown” have?

The most common answer is chesterton (10 letters).

Crossword clue: wrote father brown

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

chesterton 10 letters wd-fact-v3

conservative English writer of the Roman Catholic persuasion; in addition to volumes of criticism and polemics he wrote

author of father brown 50% similar → chesterton

wrote father sergius 50% similar → tolstoy

wrote fathers and sons 50% similar → turgenev

wrote jackie brown 50% similar → tarantino

wrote murphy brown 50% similar → bergen