For some it may come as a surprise, while some are still wondering how come it lasted as long as it did. Either way, according to Us Weekly, the cutest couple in Hollywood, Heath Ledger and Michelle Williams, broke up.

The split happened a few weeks back, a source close to the couple said, and it was obviously quiet and "amicably."

"The relationship had been rocky recently. They tried very hard to make it work but finally decided to separate. They just grew apart."

The two, who have a 23-month-old daughter together, Matilda, met on the set of 2005’s "Brokeback Mountain," also staring Jake Gyllenhaal, who is Matilda’s godfather, and Anne Hathaway.

"They have a beautiful daughter and they are both committed to being great parents," the source added.

"Matilda is adorable, and beautifully observant and wise. Michelle and I love her so much. Becoming a father exceeds all my expectations. It's the most remarkable experience I've ever had - it's marvelous," Heath said a while ago.

Despite Heath’s early claims that Michelle was his soul mate, and two fell into place like "two peas in a pod," the split was bond to happen, apparently, due to their working commitments.

"They have been filming in different locations and it has put a lot of pressure on their relationship. Heath especially is exhausted and under a lot of stress," a source was quoted by Daily Mail as saying.

Heath was previously engaged for two years to actress Naomi Watts, 37, who recently gave birth to a baby boy.