Brian Dennehy has died at the age of 81.

The iconic actor - who starred in episodes of both 'Dallas' and 'Dynasty' - passed away in Connecticut on Wednesday (15.04.20), according to TMZ.

The publication reports Brian died of natural causes, and there will not be an official autopsy.

Brian began his lengthy career in the 70s with guest roles in TV shows including 'Kojak', 'M*A*S*H', and 'Lou Grant'.

The actor starred in one episode of 'Dallas' in 1978, where he played Luther Frick, and in five episodes of 'Dynasty' in 1981 as D.A. Jake Dunham.

Brian had his breakthrough film role in 1982 when he starred in the first of the Rambo movies, titled 'First Blood' as Sheriff Will Teasle alongside Sylvester Stallone as the iconic John Rambo.

The star became known as a valuable character actor, but also achieved leading-man status in the 1987 thriller 'Best Seller', which co-starred James Woods.

Brian was also known for his role in the 1995 Chris Farley-David Spade comedy 'Tommy Boy' as Big Tom Callahan.

Most recently, the actor had played Mr. Cilliano in 2018's 'Tag', and had a role in the upcoming movie 'Son of the South', which is currently in post-production and will be a posthumous role for the star.

In television, Brian was last seen in six episodes of 2017's 'Hap and Leonard' as Sheriff Valentine Otis, and in seven episodes of 'The Blacklist', which ran from 2016 to 2019, and in which he played Dominic Wilkinson.

Brian is survived by his wife Jennifer Arnott - whom he married in 1988 - and their two children Cormack, 27, and Sarah, 25.

The 'Death of a Salesman' star also has three children, including actress Elizabeth Dennehy, with his first wife Judith Scheff.