Sir Richard Sharples, the governor of British overseas territory Bermuda, was shot dead in the capital Hamilton on this day in 1973, along with his aide-de-camp Captain Hugh Sayers.

Sir Richard, 56, and Captain Sayers, 26 (pictured above with Lady Sharples in October 1972), were murdered within the grounds of the governor’s residence Government House by an unknown assailant. As the island’s annual police ball occurred on the same night, only one armed guard was on the premises at the time.

The guard ran to the scene but found Captain Sayers already dead and Sir Richard mortally wounded. The gunman had also killed the governor’s pet Great Dane, Horsa. Road blocks were set up immediately after the incident, but the assassin was able to escape.

Civil unrest had become an occasional occurrence in Bermuda since it adopted its own constitution in July 1967. The murder of the two men came six months to the day after the island's British police chief, George Duckett, was himself shot dead.

[Read more: August 27, 1979 - Lord Mountbatten is assassinated by IRA bomb on family fishing trip]

Sir Richard, a former Conservative MP for Sutton and Cheam, had served as Minister of State in the Home Office in Edward Heath’s government, before giving up his seat to take up the role of governor in October 1972. He was buried in the town of St George’s six days after the assassination.

Elements of the British Army's airborne forces, which were on the island for training exercises with the Bermuda Regiment at the time of the murders, were called in to assist civil authorities in the hunt for the killer. A team of Scotland Yard detectives also flew in to help with the investigation.

Despite this, it was two years before the suspects were apprehended. Erskine Durrant ‘Buck’ Burrows was found guilty of the murders, as well as those of Duckett and a supermarket owner. He and another arrested Bermudian, Larry Tacklyn, were said to be members of a militant group called the Black Beret Cadre.

Although a petition signed by over 6,000 islanders requested clemency, the two men were hanged in December 1977. Two days of rioting followed their execution, which resulted in damages costing around $2 million.