Film director Ken Loach has criticised the current crop of TV period dramas for indulging in "fake nostalgia".
In response to a question about Downton Abbey in a Radio Times interview, Loach said: "This rosy vision of the past, it's a choice broadcasters make.
"'Don't bother your heads with what's going on now, just wallow in fake nostalgia. It's bad history, bad drama. It puts your brain to sleep."
Period dramas such as Victoria and Poldark have been a ratings success.
Other hit series include ITV's Downton Abbey and Mr Selfridge and the BBC's Call the Midwife and War and Peace.
Loach said nostalgic dramas were "the opposite of what a good broadcaster should do, which is stimulate and invigorate... TV drama is like the picture on the Quality Street tin, but with less quality and nothing of the street".
The filmmaker also said broadcasters should "diversify" so regions could create their own dramas, adding: "Now the drama is produced by outside production companies and horribly micro-managed.
"The directors I know in television say it's a nightmare. That's true for all the broadcasters, but the BBC is a rotten place for a director."
Loach's I, Daniel Blake, which was co-produced with BBC Films, won the Palme d'Or at Cannes Film Festival earlier this year.
His other films include Kes, Land and Freedom, My Name is Joe and Sweet Sixteen.
Loach's breakthrough came with his 1966 BBC landmark play Cathy Come Home, which tackled the issue of homelessness.