Laura Carmichael couldn't believe she had a 'proper part' in Downton Abbey

Laura Carmichael couldn't believe she had a "proper part" in 'Downton Abbey' when she was first cast in the show.

The 36-year-old actress played Lady Edith Grantham on the hit ITV period drama from its inception in 2010 and reprised the role across its two spin-off films, but she was "star struck" to have been cast alongside industry stalwarts such as Dame Maggie Smith and Hugh Bonneville.

She said: "It's been such a gift being in 'Downton'. It's opened so many doors. If another period drama came across my desk … if I loved the script, I wouldn't be too nervous of entering that world. But at the moment I'm drawn to things that feel different.

"When the 'Downton' audition came up, I couldn't have been more surprised that it was for a proper part – I thought I'd have a line or two. At the time, I didn't know what it would mean to join a cast like that. Thank God I didn't, or I'd have thrown up immediately! It was a life-changing moment. I was starstruck by the cast and constantly surrounded by brilliant actors. It was such a gift.'"

Laura - who has been dating 'Downton Abbey' co-star Michael C. Fox since 2014 and has 17-month-old son Luca with him - also plays the role of socially-isolated supermarket worker Agatha opposite Jessica De Gouw, as successful blogger Meghan, in 'The Secrets She Keeps'.

The star admitted she enjoys "trying on different hats" as an actress.

She told RadoTimes.com: "I like trying on different hats. The series works around themes that are universal. Women presenting as perfect, then having their worlds crashing down."