Early on Monday morning Graham Hughes was stamped into South Sudan, his last country, and the world's newest, which did not even exist when he started out on New Year's Day 2009.
Since then, Mr Hughes, 33, has visited all 193 United Nations member states and Taiwan, Vatican City, the Palestinian territory, Kosovo, Western Sahara and the four home nations of the United Kingdom.
The entire journey, which cost an average of £10 a day, was by train, bus, taxi or ship and at no point did he travel by air, meaning that he created a new Guinness World Record.
Mr Hughes, who presents the TV show Graham's World for the National Geographic channel and charts his progress on his website The Odyssey Expedition, is even refusing to fly now he has achieved his goal, and will instead continue through Africa and across Europe by bus and boat, aiming to return home to Liverpool by ferry from Dublin in time for Christmas.
"The main feeling today is just one of intense gratitude to every person around the world who helped me get here, by giving me a lift, letting me stay on their couch or pointing me in the right direction," Mr Hughes told The Daily Telegraph from Juba, South Sudan's capital.
"There were times, sitting in a bus station in Cambodia at one in the morning, riding some awful truck over bad roads, when I thought, why am I doing this? But there was always a reason to keep going."
Highlights were swimming in a lake of jellyfish in the Pacific archipelago of Palau, watching one of the last Space Shuttle launches from Cape Canaveral, and dancing with the jungle tribes of Papua New Guinea.
"People asked me how I was going to get to Afghanistan or Iraq or North Korea, but they were the easy ones, you don't even need a visa for Iraq, you just walk across from the border in Turkey," he said.
"The really tough ones were places like Nauru, and the Maldives and the Seychelles, island countries where there were also pirates."
To cross oceans, Mr Hughes hitched lifts with cargo ships. He spent four days in an open fishing canoe from Senegal to Cape Verde, and was then arrested when he arrived.
Later, officials in the Democratic Republic of Congo jailed him for six days believing he was a spy.
The hardest point, "when I just wanted to give up", he said, was after his older sister, Nicola, died from cancer two years ago at the age of 39. Mr Hughes rushed home to see her before she died.
"She told me not to stop the trip, but I was at a real low point. I'd done 184 countries and had only 17 to go and I thought why not leave it there," he said.
The memory of his sister spurred him on, as did the people that he met as he travelled and the money he was raising for the British charity Water Aid.
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