David Baldwin’s father, Sir Peter Baldwin, was a codebreaker, interpreting Japanese “purple” messages picked up in Bermuda during the Second World War.

His great uncle on his mother’s side, Sir Edward Wilshaw, was the chairman of Cable & Wireless Ltd, the company that redirected those same messages by underwater cables to Porthcurno, in Cornwall, England.

Mr Baldwin, Serjeant of the Vestry of Her Majesty’s Chapel Royal at St James’s Palace, had always found the “strange”, “albeit remote” connections his family had with Bermuda interesting.

And so when the Reverend Canon David Raths, the former minister at St Peter’s Church, mentioned “a rather interesting document from a silversmith, a gentleman by the name Dr Thomas Sinsteden”, Mr Baldwin’s ears pricked up.

The find led to The Serjeant’s Cup, an award given to the winner of The Marine Art Prize hosted by St Peter’s Church, Their Majesties Chappell in partnership with Bermuda Arts Centre. The winner of this year’s competition will be presented with the Cup on Sunday.

Dr Sinsteden, a renowned silversmith, had been “poking about” when he came across a warrant from the Bishop of London to supply “Their Majesties Chappell” with a chalice and other sacramental vessels.

The warrant, dated 1697, was “fascinating because of its terminology” used to describe St Peter’s, the oldest Anglican church in continuous use outside Great Britain.

Queen Elizabeth II was fearful that the term would fall into disuse and decided to retitle the St George’s church on the occasion of her Diamond Jubilee.

“[The phrase] hadn't been used in hundreds of years and she thought it would be nice to have that restored properly by her own warrant signed to it,” Mr Baldwin said.

“It fell to me to sort of bring all this together as the Serjeant of the Chapel Royal in the royal household, who had custody of the ecclesiastical records of the sovereigns.”

Mr Baldwin drew up a charter and presented it to Queen Elizabeth II for approval.

“It was designed to be all-ranging and all encapsulating, just a nice title that everybody in the island could appreciate as part of their heritage,” said Mr Baldwin, who hand-delivered it to St Peter’s Church in 2012.

It was in preparing the charter that he decided to make a contribution of his own and had The Serjeant's Cup for Marine Art engraved. With his own title in mind Mr Baldwin decided to use “serjeant”, a spelling introduced by William the Conqueror when he invaded Great Britain in 1066.

“So it’s the Serjeant's Cup for Marine Art and the idea was any Bermudian from whatever background or status or anything else could paint, in a competition for which this cup will be given to the best,” he said.

The competition is held without age or other restrictions.

“I liked the idea of marine art because it’s all inclusive; it doesn’t exclude anybody’s talent from any quarter and I think local Bermudians seem to have rather embraced it.”

Now in its tenth year, the exhibit has continued through the “generosity and kindness” of Bermudians.

“People like Gillian Outerbridge in particular have made it their mission to see that this cup is competed for and then given,” said Mr Baldwin, who retired from the royal household in 2016.

“So that's the background to it, but I had it specially engraved before coming across. So it was all done in advance, without any knowledge of David Raths or anybody else – that came as a surprise. But it was designed to keep Bermudians happy and engaged in something which they may find they’ve got a [talent] for, which is painting.”

His “slight family link with Bermuda” was another reason that Mr Baldwin felt his gift was appropriate.

In 1944 the US Navy captured a U505, a German submarine, off the coast of Casablanca.

“The problem with that is it happened on June 4, two days before D-Day; the massive liberation of Europe was only two days after this capture. So they had to make it look as though the Americans had actually sunk this U-boat or else the German Kriegsmarine high command would change all the Enigma codes and the Japanese would do likewise and that would then compromise all the reading of symbols that we could do,” Mr Baldwin explained.

A “very grand exercise” ensued. The Americans brought the submarine to Bermuda, where it was painted to look like one of their own vessels and secured safely in Dockyard.

“That saved any potential disaster for the D-Day landings, two days later, over in the English Channel. Father was involved because he was a codebreaker at [Bletchley] Park, Station X, here in the UK, and he was put on the Japanese diplomatic codes to break and he contributed a lot to that,” said Mr Baldwin.

Sir Peter, who knew no Japanese at all, had three weeks to learn it.

“[Codebreakers] had to look for random numbers, which would nevertheless represent some difficulty for the Japanese. So father was involved in all that because Bermuda had a special role – it was a sweet spot for intercepting signals intelligence emanating from Japan. Just the way the atmosphere went around the globe. And of course, when it was intercepted there it had to be retransmitted over to the UK or any of its listening posts.”

It’s there that his mother Margaret’s family became involved. As head of Cable & Wireless Sir Edward was responsible for “putting the tunnels to put all the telegraph company's cables in at Porthcurno in Cornwall in 1940”.

Tunnels were dug across the Atlantic and the Mediterranean by 200 tin miners from Cornwall, qualified to ensure that the tunnels would not get bombed or destroyed.

“But that was Uncle Teddy, he was the man in charge of all that. It so happened that certain signals that were intercepted in Bermuda were transmitted eventually to Porthcurno and then to Bletchley Park,” Mr Baldwin said.

“So father found himself receiving signals that had come through a sort of family connection in a funny kind of way. It really is quite bizarre. So there were these sorts of strange connections with Bermuda, which the family had, although remote. They’re all part of the reason to try and do something which would help all Bermudians.”

• The Serjeant’s Cup and other cash prizes will be presented at the Bermuda Arts Centre at Dockyard on Sunday from 3pm until 5pm. The exhibit runs until June 7. For more information call 534-2809