Prince William Seen Leaving Hospital After Visiting Kate Middleton

Prince William went to go see his wife, Kate Middleton, a day after it was announced she's going to be in the hospital for a while -- marking the start of what may be recurring visits.

His Royal Highness was photographed Thursday leaving the London Clinic ... this after dropping in for some facetime with the Princess of Wales, who just went through an operation -- and who'll remain under a doctor's watch for the next 2 weeks.

As you can see, Will was cruising in his own car with security personnel following close behind in a separate vehicle. He had a passenger with him ... but PW was behind the wheel.

It's no surprise that he's hitting up the hospital to see the missus -- frankly, the surprise news that she'd be bedridden for this long to recover came as a shocker ... indicating that whatever she's dealing with was quite serious. So, he was bound to arrive sooner or later.

Again, Kensington Palace didn't provide details about Kate's condition ... other than to say the abdominal surgery she received was scheduled, and that the procedure was successful.

They stressed she wouldn't be able to resume her Royal duties or attend engagements until after Easter ... and the Palace asked for privacy too. Not long after that, it was announced that King Charles was also going under the knife to deal with an enlarged prostate.