CREATE TABLE table_8042 ("Name" TEXT, "Death" TEXT, "Assumed Office" TEXT, "Left Office" TEXT, "Years in office" TEXT, "Monarch" TEXT)

Which monarch assumed office on December 15, 1876?
SELECT "Monarch" FROM table_8042 WHERE "Assumed Office" = 'december 15, 1876'
SELECT "Monarch" FROM "table_8042" WHERE "Assumed Office" = 'december 15, 1876'