What is the name of the queen regnant?
CREATE TABLE "list_of_state_leaders_in_840s_bc" (
  "type" text,
  "name" text,
  "title" text,
  "royal_house" text,
  "from" text
);
SELECT "name" FROM "list_of_state_leaders_in_840s_bc" WHERE "title"='queen regnant';