Dune II was first released in 1992 for MS-DOS; later for Amiga, Mega Drive, and RISC OS.
Dune II went on to form the basis of the gameplay mechanics of Westwood Studios' later command-and-conquer series of games. It's often called the first rts by fans, and though there were earlier RTS games, it originated many of the elements that are tiday considered integral to the genre.
See also Dune II on Wikipedia.
