Alexander Marcus

Alexander Marcus was a Human who lived in the 23rd century. He was married to a woman whose maiden name was Wallace. He was the father of Carol Marcus and the grandfather of David Marcus. 

Background information
Alexander Marcus was only seen onscreen in Star Trek Into Darkness, which is set in the alternate reality. Memory Alpha assumes Carol Marcus' parents are the same in the prime reality, so the only things known about this version of him are his familial connections.

The Star Trek iTunes app states joined Starfleet in 2223, indicating that Alexander Marcus was already in Starfleet at the time and that Pike's prime counterpart was also inspired by Marcus to enlist.