CREATE TABLE table_name_84 (marriage VARCHAR2, became_queen VARCHAR2)

How is the marriage of who became queen on 30 October 1816 husband's accession?
SELECT marriage FROM table_name_84 WHERE became_queen = "30 october 1816 husband's accession"
SELECT "marriage" FROM "table_name_84" WHERE "30 october 1816 husband's accession" = "became_queen"