They all serve in the 1st Battalion, The Welsh Guards, which guards the Queen, performing ceremonial duties at her home and based near her Windsor residence.
One of the 13 jailed soldiers even took part in the Queen’s Birthday Tribute televised parade in Windsor in June – it is believed to be the first time it has been performed at the castle.
Their battalion also took charge of London’s first Covid-19 mobile test centers earlier this year and is preparing for a grueling deployment to Iraq next year.
While incarcerated, soldiers will have their wages cut in accordance with military law, which means they will lose half a month’s wages.
Defense sources confirmed that four of the men would have tested positive for cocaine and would be expelled from the military after serving their sentences.
Their punishment came after officers investigated their afternoon’s football game in a park, just days after the Queen’s tribute in June, on the bank of the Thames.
Sources say they are jailed for not distancing socially as with civilians in a post-football drunken session, they put the rest of their battalion at risk.
The 13 soldiers were convicted by their commanding officer after being questioned in a courtroom-style military summary hearing at their Windsor barracks late last week.
They will each be locked up for 14 days without pay at the Armed Forces prison, Military Corrective Training Center, Colchester, for violating Covid regulations.
The men threatened with prison have had two weeks to prepare for their sentence during which the troops are subjected to strict and punitive physical training.
Sources told the Daily Mirror that the harsh punishment was due to the troops mingling with civilians during the June holiday as it meant they mingled outside their home.
A former soldier told the Daily Mirror today: “There is a lot of anger in the lower ranks of the battalion at the harshness of these sentences.
“Look at how little punishment civilians get – and these guys have lost half their monthly salary and are sentenced to two weeks in military prison.”
But high-level sources in the Defense Ministry said the troops could have put other comrades at risk of spreading the virus, especially since they are playing for the Queen.
The troops are believed to have traveled to an area on the Thames bank that has become popular with civilian revelers who routinely break social distancing rules.
The 1st Battalion Welsh Guards – motto Wales Forever – is currently stationed at Combermere Barracks, near Windsor Castle.
Prince Charles is the Ceremonial Royal Colonel of the Welsh Guards Regiment and is a senior official in the UK Households Division.
A summary hearing takes place when the commander acts as judge and jury, passing sentence after hearing the testimony of soldiers represented by officers.
A decision regarding the other three defendants will be made in the coming days.
Although military prison sentences will remain in the records of the troops, they do not lead to a civilian criminal record as they are punished in accordance with military law.
A British Army spokesperson said: ‘We are proud of our armed forces for the support they have given to the NHS in response to Covid-19, but we demand the highest standards of behavior in all of our staff.
“Following a breakdown in social distancing by several Welsh guards, an investigation was conducted and the incident was dealt with internally.”