What is "swiebertje"

Swiebertje is a character and eponym from the books of Dutch author John Henri uit den Bogaard, who wrote a series of children's books based on the character from 1936 to 1974. The books were adapted for television ( Joop Doderer playing the title role), in a series of shows which aired on NCRV in the 1960s and 1970s, one of the longest-running and most popular shows in Dutch TV history.