Howard Stark

Howard Stark is Tony Stark's father as well as the founder of Stark Industries. He has been an influential figure in the Marvel universe's history.

Iron Man
Before Tony award, seen some pictures of Howard as: working, with his business partner Obadiah Stane and a newspaper clipping reporting his death and his wife.

Iron Man 2
Tony sees a video of his father talking about the discovery of a new element but he could not synthesize it, at the end of the video, Howard says that Tony is and always will be his greatest creation.

Captain America: The First Avenger
Howard was present when Steve Rogers was injected with the Super Soldier Serum. Stark was responsible for the construction of the Captain America's Shield made of vibranium. After the disappareance of Rogers, Stark finds the Tesseract in the ocean.

Captain America: The Winter Soldier
After escaping from the Strike team, Natasha and Steve arrive at Camp Lehigh. There they discover that S.H.I.E.L.D. originated in that place. In that it is revealed that Arnim Zola even still alive thanks to technology.

Steve asks him how came to USA and Zola reveals that thanks to an iniative of Howard Stark, which consisted in recruiting repentant nazi scientists. Arnim Zola reveals to Rogers that HYDRA was involved in the death of Howard Stark and his wife, Maria.

Trivia

 * Howard Stark, like many other characters from the Marvel Cinematic Universe, was played by different actors in different movies. The others are Thanos, Fandral, Bruce Banner and James Rhodes.
 * Howard Stark's appearance and personality in Iron Man 2 were based on Walt Disney.