08/30/2013 at 10:55 AM EDT
Clint and Dina Eastwood have decided to separate after 17 years of marriage.
The Trouble with the Curve
star, 83, and his wife, 48, have been living apart for some time, PEOPLE confirms.
"This is really sad," a source tells PEOPLE. "They were great partners for many years."
Last week she posted a Tweet
with the hashtag "newbeginnings: "Darkness somewhere means light somewhere else."
The couple were married in 1996 and have one daughter, Morgan, 16.
In 2012, the Eastwoods debuted their E! reality show Mrs. Eastwood & Company
starring Dina, Morgan, and Francesca Eastwood
, 19, who is Clint's daughter from a previous relationship with actress Frances Fisher.
Clint has a total of eight children, who have appeared on the show. The Dirty Harry
actor was noticeably absent from the reality series, though he did make a brief appearance in the first episode.
Reporting by OLIVER JONES