Bosses of the hit period drama announced on Thursday (26Mar15) that the sixth series will be the last and the remaining nine episodes, including the 2015 Christmas special, will be focused on tying up the characters' story lines.

Bonneville, who has been filming the final series for seven weeks, admits he knew the show was coming to an end a while ago because creator Julian Fellowes asked to extend his contract one more time to give his character Robert Crawley a proper farewell.

The actor tells U.K. TV show Good Morning Britain, "It's finally been announced that it's coming to an end... We were amazed it went beyond series one... There was no guarantee the show was going to continue. After a couple of years the producers said 'We'd like to extend it a bit more' and Julian Fellowes said 'I'd like to do a bit more'... it's still so loved around the world and really when it came towards the conclusion of our last contract, Julian personally said, 'I want to write one more, there's one more push I want to do in terms of bringing the characters into land properly rather than rushing it' and that's what we're doing now... It's going to be quite an extraordinary experience."

When asked if he knows how the show will end, he replied, "I don't. We've only read up to episode six of the nine, nine being the Christmas special."