Risca residents gave a warm welcome to to the unit, which has returned from a tour in Afghanistan.
The Royal Air Force held a special service to mark decades of life and work at the base.
There are concerns that plans to pull 600 military personnel and close a base will have a 'devastating affect' on Pembrokeshire
Crowds have gathered in Risca today for a special parade and medal ceremony to honour the 203 (Welsh) Field Hospital's homecoming from a tour of duty in Afghanistan as part of Operation Herrick.
Crowds in Risca await a homecoming parade from 203 (Welsh) Field Hospital http://t.co/Uq1R8IMQBx
Huge turnout in Risca today http://t.co/XG908Z3dpY
More than 100 military personnel are taking part in the Risca parade http://t.co/h70mHh2iZI
The Defence Secretary has told ITV News lessons have been learnt when it comes to military training exercises.
It follows the Health and Safety Executive's criticism of the way risks were assessed during an SAS selection exercise in the Brecon Beacons in July, which left three reservists dead.
Today Philip Hammond said reservists can be confident that changes have been made.
The notice served by the Health and Safety Executive says the Ministry of Defence:
- Failed to make a suitable and sufficient assessment of the risks to the health and safety of employees, namely those soldiers participating in the aptitude phase in the Brecon Beacons on July 13
- Failed to properly identify the risks associated with the activity and implement effective measures to control them, including those relating to heat illness
- Failed to review the risk assessment when it became clear persons participating in the test were suffering from heat illness
The HSE notice went on: 'These contraventions are likely to continue or be repeated during the planning of, training for and carrying out of future selection tests of this nature'.
The Ministry of Defence has released a statement saying it will implement all of the HSE's recommendations.
– Ministry of Defence spokesperson
Our thoughts remain with the families of those who died on this exercise.
We have co-operated fully with the Health and Safety Executive inspectors and are implementing all the recommendations in the Crown Improvement Notice.
As the incident is still subject to a Police and MOD investigation it would be inappropriate to comment further.
– Health and Safety Executive spokesperson
HSE has issued a Crown Improvement Notice on the Ministry of Defence following the deaths of three Army reservists while on selection tests on the Brecon Beacons in July.
The notice requires the Ministry to take action to deal with risks arising from its military selection exercises.
HSE continues to investigate the deaths, supporting Dyfed Powys Police which is leading the investigation.
The Ministry of Defence has been ordered to make immediate changes following the deaths of three Army reservists who fell ill during SAS selection tests on the Brecon Beacons.
Craig John Roberts, 24, Edward John Maher, 31, and James Dunsby, 31, all died after becoming unwell in July on one of the hottest days of the year.
The Health and Safety Executive has now issued the MoD with a Crown Improvement Notice, which requires it to take immediate action to deal with potential risks arising from its military selection exercises.
A joint Health and Safety Executive (HSE) and police investigation into the circumstances surrounding the soldiers' deaths is continuing.
A third soldier who died following an SAS reservist training exercise in the Brecon Beacons suffered multiple organ failure, an inquest has heard.
Corporal James Dunsby died in hospital 17 days after collapsing on Pen Y Fan on 13th July. Lance Corporals Edward Maher and Craig Roberts also died in the incident.
The opening of an inquest into Cpl Dunsby's death at Aberdare Coroner's Court heard that the 31 year old was one of six soldiers to collapse on Pen Y Fan.
Coroner Louise Hunt said a post-mortem found his died of "multiple organ failure." The inquest was adjourned until September. A full inquest into the deaths of all three men will be held at a later date.
Tributes have been paid to 31-year-old Corporal James Dunsby, who died yesterday in hospital after falling ill during SAS selection training in the Brecon Beacons.
In a statement released through the Ministry of Defence, his family said he "adored the Army" and had the "most infectious enthusiasm for life".
He was the most loving and dependable husband, not to mention the most handsome of men of whom could not be more cherished.
James was and will remain a dearly loved, son, brother and husband. He had the uniquely wonderful ability to endear, enchant and captivate all who he met with his naughty sense of humour and highly intelligent wit.
With James as your friend you were ensured loyalty, strength, allegiance, protection and most of all a damn good laugh.
– Family statement
James adored the army and believed so passionately in his duty as a protector of Queen and country and of the realm.
James was so dearly loved by so many and will be sorely missed. Hurrah and Huzzah for James Dunsby; a greater man you could not meet.
We ask to be allowed to come to terms with our grief and loss of our beloved son and brother James.
Corporal Dunsby had been in a serious condition in hospital after falling ill during the exercise on July 13 - one of the hottest days of the year.
His death follows that of colleagues Edward John Maher and Lance Corporal Craig John Roberts.
A third army reserve soldier who died after taking part in SAS selection training in the Brecon Beacons has been named by the Ministry of Defence as Corporal James Dunsby.
Corporal Dunsby had been in a serious condition in hospital since falling ill during the training on July 13th.