CREATE TABLE table_6450 ("Birth" CLOB, "Marriage" CLOB, "Became Duchess" CLOB, "Ceased to be Duchess" CLOB, "Death" CLOB, "Spouse" CLOB)

Who is the Spouse of the Duchess that has a Birth on 29 october 1451?
SELECT "Spouse" FROM table_6450 WHERE "Birth" = '29 october 1451'
SELECT "Spouse" FROM "table_6450" WHERE "Birth" = '29 october 1451'