Congratulations are in order! Downton Abbey star Allen Leech is officially engaged to his girlfriend, Jessica Blair Herman, and we couldn't be happier for the couple.

Allen —who plays Tom Branson on the hit TV show — confirmed the news in a sweet Valentine's Day Instagram tribute. "Happy Valentine’s Day @jessicablairherman First one as a fiancé! Thank you for saying yes and for making me the happiest," he wrote alongside a beautiful portrait of the two, where Jessica showed off her pretty ring. The pair began dating in 2016.

The 36-year-old actor then assured fans he didn't do a Valentine's Day proposal. Turns out, they've been engaged for quite some time! "And no I didn’t do it today. It’s been a while," he mentioned at the end of the caption. He didn't specify when he got down on one knee, but we bet it was super romantic!

Jessica — who you may recognize from American Crime Story and Modern Family —reciprocated with a very sweet note to her fiancé. "The day you proposed was one of the best days but every day with you is my favorite. I love you! Happy Valentine’s Day @therealleech! ❤️" she wrote alongside a photo of Allen kissing her on the cheek.

Allen previously dated sports presenter Charlie Webster, but their late 2015 split ended amicably. After their breakup, she confessed to The Mirror, "We had an amazing time. There is no bad feeling at all. We are both very career minded." Charlie added, "Downton Abbey has just finished and he is going to go on to a huge career. And my career is really exciting. It was the wrong time for either of us to be in a long-term relationship."

We can't wait for Allen and Jessica's big day!