The character of Baron Helmut Zemo made its debut in the big Marvel cinematic universe, although he was referred to as Zemo in the Civil war movie. The tone of the movie was similar to Captain America Winter soldier i.e a sleek political thriller with superhero elements poured over it. He was played by actor Daniel Bruhl who appeared in movies like Rush, The Fifth Estate etc. He has solid affiliations with HYDRA and Masters of Evil in the past. He is the 13th Baron Zemo, son of Baron Heinrich Zemo who was a master Nazi scientist during the World War 2 and an enemy of Captain America. The Zemo dynasty is similar to Strucker family passing the mantle from one generation to another.
He played a big role in the Sokovia Accords i.e set of internationally ratified legal documents that provide regulation and framework for the military deployment of enhanced individuals and maintaining international rules of combat in the event of a war. It was particularly meant to control the unlimited powers enjoyed by superhero teams like Avengers, drafted by UN & signed by over 170 countries in the wake of a trail of devastation left by Ultron in the Battle of Sokovia. He has been trying to extract more information about the possible hit performed by Winter soldier in the 1990’s.
Black Panther saw his father dying in an explosion before his own eyes at the time of UN Special Panel meeting where they gathered to ratify Sokovia accords to bring oversight into the supposedly unilateral actions of the Avengers. The man responsible for it was Baron Zemo who lost everyone in the family during the Wakanda showdown with Ultron and hold Avengers responsible for his personal loss. He framed Winter soldier for the incident which set off a chain of events pitting Team Cap against Team Iron-man.
There is a big section in the Marvel fan community who felt that he isn’t menacing enough and has no superpowers to challenge Avengers. He was apprehended by Black Panther once his plans became public, but the enormous amount of damage was already done. He successfully created fissures in the Team Avengers which led to Steve Rogers parting ways with S.H.I.E.L.D. He did what Ultron couldn’t i.e destroying the Avengers from the inside and he did that without any allies. CHEERS!