[1][2][3] On 6 June 1944 Mayhew commanded a company equipped with 13 armoured infantry carriers that landed at Sword Beach in Normandy, on D-Day.

[1][2] His unit captured the Hillman Battery, a 12-bunker complex defended by 150 men of the 736 Infantry Regiment, as part of the liberation of Colleville-sur-Orne.

[1] The 1st Battalion were supposed to meet airlifted troops at Arnhem as part of Operation Market Garden, which failed however.

During battles in the Netherlands Mayhew's company took part in the liberation of Weert (22 September), Venray and Overloon (16–19 October).

[5] The Order is the highest and oldest military honour of the Kingdom of the Netherlands, bestowed for "performing excellent acts of Bravery, Leadership and Loyalty in battle".

[6] In the words of the royal decree:[7][8] During combat to liberate occupied Dutch territory he [Mayhew] distinguished himself by committing excellent acts of bravery, leadership and loyalty.

[1] In 1965, in honour of the 150-year anniversary of the Military William Order, Mayhew was received by Queen Juliana of the Netherlands at Huis ten Bosch.

Mayhew was eventually presumed dead and went unnoticed when he attended the unveiling of a monument in honour of the Suffolk Regiment in Weert in 1994.

[3] While attending a memorial service at Venray in September 2011, Mayhew was seen by Dutch medal researcher Roel Rijks and Henny Meijer wearing the decoration of the Military William Order.

[14] Later that month Mayhew baptised tulips in London, a gift from the Netherlands to mark the 70-year anniversary of Operation Market Garden, attended by representatives from the Dutch, British, Australian, Canadian, New Zealand, Polish and US armed forces.

The event, which was broadcast live on Dutch national television, saw Mayhew welcoming Tuinman as a new member of the order.

[17] In honour of his 100th birthday, King Willem-Alexander of the Netherlands sent Mayhew a congratulatory letter in January 2017, which was delivered by the Dutch ambassador to the United Kingdom.

[18] Mayhew was a guest at Buckingham Palace during the state visit of King Willem-Alexander of the Netherlands and Queen Máxima to the United Kingdom in October 2018.