'X-Men: Apocalypse' will be the last part of a trilogy that began with 'First Class', according to writer-producer Simon Kinberg.

The 41-year-old explained that the third installment in the series will conclude the storylines that began in Matthew Vaughn's 2011 film.

The London-born writer told Yahoo: ''The thrust of [Apocalypse] is really to complete the trilogy we began with 'First Class' - to complete the stories of young Raven, young Hank, younger Charles and Erik.

''And complete this trilogy of four people who began the films in sort of disparate and in different worlds - even if they knew each other, in the case of Charles and Raven.

''We've followed them over what will be the span of decades... So really that'll be the thrust of that film. There will be familiar characters and new characters that we haven't seen... ever... but it'll be the completion of what we began in First Class.''

The 'X-Men' trilogy has featured a host of big name actors and actresses, including James McAvoy, Michael Fassbender, Jennifer Lawrence and Nicholas Hoult.

'X-Men: Apocalypse' is set to debut in UK cinemas on May 19, 2016, and in the US on May 27.