On April 21, 1820, Hans Christian Oersted was delivering a lecture when he first noticed that a compass needle deflected from magnetic north when the electric current of the battery was switched on and off. This confirmed a direct relationship between electricity and magnetism.
Oersted first thought that magnetic effect radiate from all sides of a wire carrying electric current but later when he did his research, he found out that electric current produces a circular magnetic field as it passes through the wire.
Apart from electromagnetism, Oersted also discovered aluminium. Humphry Davy had first discovered the alloy aluminium-iron. However, Oersted was the first person to isolate aluminium from an alloy of aluminium chloride.
Thus, Hans Christian Oersted has indeed made some important contributions without which we cannot possibly imagine today's life.