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

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'