2020: Hussein took this "one in a million" photo during Harry and Markle's farewell tour on March 5.
Prince Harry and Meghan Markle at The Endeavour Fund Awards.
Samir Hussein/WireImage/Getty Images
2019: They showed spontaneous PDA during an official visit to Morocco on February 24.
The Duke and Duchess of Sussex during their visit to the Atlas Mountains.
Samir Hussein.
"2019 bought the arrival of baby Archie, but it was while Meghan was heavily pregnant that one of the great images of the pair of them came about," Hussein said.
"Harry and Meghan were on a visit to Morocco and visited the stunning Atlas Mountains. While watching school children play football, Meghan leant into Harry and lay her head on his shoulder while he looked back at her grinning.
"It was a spontaneous and lovely moment and the kind of public display of affection that is rare amongst the Royal Family," he said.
2018: Five months after their royal wedding, the happy couple appeared more loved up than ever on Bondi Beach in Australia on October 19.
Harry and Markle at Bondi Beach.
Samir Hussein
"[This was] the year Harry and Meghan got married with the wedding in May, producing so many memorable images," Hussein said.
"For me, however, my favorite moment of the two of them came a few months later on Bondi Beach in Australia.
"Happily married and days after announcing they were expecting their first baby, Harry and Meghan relaxed barefoot on the sand of Bondi Beach with a group of surfers promoting mental health.
"This moment where they turned and smiled at each other produced a tender and authentic photo capturing their love," he said.
2017: Harry and Markle made their engagement official with a photo call outside Kensington Palace on November 27.
Prince Harry and Meghan Markle at their engagement photo call.
Samir Hussein/Getty Images
"This was the year Harry and Meghan made their relationship official," Hussein told Insider.
"I was in Toronto to photograph them watching the wheelchair tennis at the Invictus Games when they stepped out together for the first time in an official capacity.
"Interest in Harry and Meghan soared as a result, culminating in them announcing their engagement in the gardens of Kensington Palace.
"This photo I took of them summed up the excitement of that day and their shear joy at getting engaged," he added.