He was responsible[1] for the King David Hotel Bombing in 1946, which was for decades known as the deadliest terrorist attack of the 20th century.

He is known in academia as a founding figure of modern terrorism who set the mold which others, many of whose political opinions were diametrically opposed, would later employ.

Begin’s most significant achievement as prime minister was the signing of a peace treaty with Egypt in 1979, for which he and Anwar Sadat shared the Nobel Prize for Peace.
http://en.wikipedia.org/wiki/Menachem_Begin