The first "artificially" created element was technetium which was in 1937 by Carlo Perrier and Emilio Segrè. Strictly speaking "artificial" may not be entirely accurate as under certain circumstances one would expect the element to be created in nature. However, technetium, has no stable isotopes and therefore decays over time. Some purists would argue that technetium is not artificial because it has been found in trace amounts on Earth.