Superboy began publication in March-April of 1949. At first published as a bi-monthly comic book, DC began scheduling Superboy for eight issues a year beginning with issue #29. By 1966, DC began distributing nine issues of Superboy per year and the title eventually became a monthly series in 1972. By issue #197, Superboy began having adventures in the 30th century with his friends, the Legion of Super-Heroes. Beginning that same issue, the Legion became reoccurring characters in the series, and even shared cover credit on each issue. By the end of 1979, Superboy returned to the 20th century, and with issue #259 the series became known as the Legion of Super-Heroes.