  The long history of the research concerning the possible existence of bound
or resonant states in light multineutron systems, essentially $^3$n and $^4$n,
is reviewed. Both the experimental and the theoretical points of view have been
considered, with the aim of showing a clear picture of all the different
detection and calculation techniques that have been used, with particular
emphasis in the issues that have been found. Finally, some aspects of the
present and future research in this field are discussed.
