One of Hollywood's most well-known couples, Catherine Zeta-Jones marriage to Michael Douglas has certainly withstood the test of time, and it's today that the couple can say that they're celebrating 15 years of wedded bliss - though it hasn't exactly been without its pitfalls.

Catherine Zeta-Jones And Michael DouglasCatherine Zeta-Jones And Michael Douglas celebrate 15 years of marriage

46-year-old Jones married Douglas, who is exactly 25 years her senior since they share a birthday, this very day (November 18th) in 2000 in a ceremony at the Plaza Hotel in New York City. It came as soon as Douglas' divorce from Diandra Luker was finalised and since then, the couple have been virtually inseparable - that was until news broke in 2013 that they had separated for a few months.

The couple, who have two children - 15-year-old son Dylan Michael and 12-year-old daughter Carys Zeta - were confirmed to have been living separately in Spring 2013, but no legal action regarding divorce was ever filed. Now it seems that are living happily together again and enjoying their 15 years of marriage, with no plans of breaking up anytime soon.

With such a big age difference between them and nearly two teenagers, the couple were always going to have some problems in their relationship. But their marriage was rocked badly by Jones' diagnosis of bipolar II disorder in 2011, for which she stayed in rehab during her separation to Douglas.

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Not only that, but a year before Douglas himself experienced serious health issues when he was diagnosed with tongue cancer; a disease which caused him to lose a large amount of weight before he was finally given the all clear.

So, it's been a tough ride, but the pair seemed happier than ever as they posted an old black and white snap of them on Instagram. 'Happy Anniversary dearest Michael! Loving our life together, here's to the next 15', Jones captioned the pic.