Tom Cruise writes to Katie Holmes
"I think it's something Tom's been thinking about a lot recently, but especially as July was approaching. It's like he's finally recognised that Katie will always be the love of his life," a source told LOOK magazine, reports contactmusic.com.
"It was such a shock when she left him, although she would no doubt argue that he ignored the signs, terms with that decision but I think Tom finally understand why she had to end things.
"It's taken a long time for him to come to and let go of the anger, but it seems like he finally has and he obviously will have wanted to tell her that," the source added.
The couple, who reportedly only communicate via intermediaries, is said to have attempted to call a truce in March, but have barely exchanged words since.
Thrice-divorced Cruise, 50, is now more determined than ever to rekindle his friendship with Holmes for the sake of their seven-year-old daughter Suri.
They split last year.