Huh: Martin Luther King, Jr., (January 15, 1929-April 4, 1968) was born Michael Luther King, Jr., but later had his name changed to Martin.
nobel prize bio

And: One of the watershed events in Michael Luther King, Sr.'s life was his attendance at the World Baptist Alliance meeting in Berlin, Germany in 1934. In addition to seeing Europe, King and a group of ministers visited the Holy Land, an experience which solidified his commitment to his ministry. His trip to Europe was reported in the local press, which gave him an elevated social prominence when he returned to Atlanta. It was at this time of his life that he formally changed his name to Martin Luther King, Sr. (and his son to Martin Luther King, Jr.), likely when he applied for his passport to travel to Europe. (Relatives and close friends continued to refer to both Sr. & Jr. as "Mike" or "M. L." Martin Luther King, Jr. was referred to by his father as "M.L.")

link, p. 2

Still the same initials.