Sienna Miller and her partner of four years, Tom Sturridge, have split, reports Us Weekly.

The two started dating in 2011, had a child together in 2012, but seem to have hit hard times. A source close to Miller said, "They were in a bit of a rough patch for awhile. Their schedules on top of raising a child started to get to them."

We're a little shocked that the two called it quits, since our photogs caught the couple enjoying a beach vacation together on July 3, in Formentera, Spain. The duo looked quite happy playing with their daughter, Marlowe.

We have a feeling the burdens of being a mother took it's toll on the relationship. The Factory Girl told London's Time Out magazine this past January how difficult she found motherhood. "It's a shock, of course it is," she said. "Some people find it really easy, but for me I found it really hard."

Well that's too bad -- they were a good-looking couple. Maybe Sienna will hit up one of her famous exes for a rebound --we have a feeling Jude Law's always up for a romp ...