About 5,500 years ago someone in the mountains of Armenia put his best foot forward in what is now the oldest leather shoe found.
It will never be confused with a penny loafer or a trainer, but the well-preserved footwear was made of a single piece of leather, laced up at the front and back, researchers said in PLoS One, a journal of America's Public Library of Science.
Worn and shaped by the wearer's right foot, the shoe was found in a cave along with other evidence of human occupation. The shoe had been stuffed with grass, which dated to the same time as the leather of the shoe - between 5,637 and 5,387 years ago.
"This is great luck," said archaeologist Ron Pinhasi of University College Cork in Cork, Ireland, who led the research team.
He said historians normally only found broken pots and had very little information about the day-to-day activity of the ancient people.
"What did they eat? What did they do? What did they wear? This is a chance to see this ... it gives us a real glimpse into society," he said.
Previously the oldest leather shoe discovered in Europe or Asia was on the famous Otzi, the "Iceman" found frozen in the Alps a few years ago and now preserved in Italy. Otzi has been dated to 5,375 and 5,128 years ago, a few hundred years more recent than the Armenian shoe.
Otzi's shoes were made of deer and bear leather held together by a leather strap. The Armenian shoe appears to be made of cowhide, Mr Pinhasi said.
Older sandals have been found in a cave in Missouri, but those were made of fibre rather than leather.
The shoe found in what is now Armenia was found in a pit, along with a broken pot and some wild goat horns.
But Mr Pinhasi does not think it was thrown away. There was discarded material that had been tossed outside the cave, while this pit was inside in the living area. And while the shoe had been worn, it was not worn out.
It is not clear if the grass that filled the shoe was intended as a lining or insulation, or to maintain the shape of the shoe when it was stored, according to the researchers.
The Armenian shoe was small by current standards - UK size 4 - but it might have fit a man of that era, according to Mr Pinhasi.
He described the shoe as a single piece of leather cut to fit the foot. The back of the shoe was closed by a lace passing through four sets of eyelets. In the front, 15 pairs of eyelets were used to lace from toe to top.
There was no reinforcement in the sole, just the one layer of soft leather. "I don't know how long it would last in rocky terrain," Mr Pinhasi said.
He noted that the shoe was similar to a type of footwear common in the Aran Islands, west of Ireland, up until the 1950s. The Irish version, known as "pampooties" reportedly did not last long, he said.
"In fact, enormous similarities exist between the manufacturing technique and style of this (Armenian) shoe and those found across Europe at later periods, suggesting that this type of shoe was worn for thousands of years across a large and environmentally diverse region," Mr Pinhasi said.
The shoe is currently at the Institute of Archaeology in Yerevan, but Mr Pinhasi hopes it will be sent to laboratories in either Switzerland or Germany where it can be treated for preservation and then returned to Armenia for display in a museum.
Meanwhile, he is heading back to Armenia this week, hoping the other shoe will drop.
The research was funded by the National Geographic Society, the Chitjian Foundation, the Gfoeller Foundation, the Steinmetz Family Foundation, the Boochever Foundation and the Cotsen Institute of Archaeology at UCLA.