Michelle Dockery Mourns Death of Longtime Partner From Cancer

Michelle Dockery has been dating Irish executive John Dineen since 2013.

— -- "Downton Abbey" star Michelle Dockery is grieving the loss of her longtime partner, who died of cancer last weekend.

Dockery's rep confirmed the news to ABC News and released the following statement: "The family is very grateful for the support and kindness they have received but would kindly request that they are left to grieve in private."

Dockery's partner, Irish financial PR executive John Dineen, died on Sunday at the Marymount Hospice in Cork, according to the Irish Independent. He was 34.

The newspaper reported that the 34-year-old actress cut short a U.S. promotional tour for the final season of "Downton Abbey" to be by Dineen's bedside, along with his family.

The couple began dating in September 2013 after being introduced by Dockery's co-star Allen Leech, who plays chauffeur Tom Branson.

Despite reports that they were engaged, Dockery, who plays Lady Mary Crawley on the popular PBS drama, remained tight-lipped about her private life.