The former king of Greece is also from the same dynasty. Christian IX was the first king of Denmark from this branch of the house and his second son prince Wilhelm was elected to become King George I in Greece. His son Constantine I as well as three of his grandsons George II, Alexander and Paul reigned (with periods of exile in between) before his great-grandson Constantine II succeeded. He married the youngest sister of the Danish Queen and went into exile before the monarchy was abolished. A restoration of the Greek throne seems unlikely in the near future.
As prince Philip, Duke of Edinburgh is a male line grandson of George I of Greece but adopted the name of his maternal uncle Mountbatten when he became a UK citizen. After her succession HM stipulated that the reigning dynasty in the UK would retain the name of Windsor. Non-Royal male line descendants of the couple use Mountbatten-Windsor as their official surname.