As the seasons change, I see the shifts the land has taken through flooding and ploughing. A field once dismissed now displays a scattering of pottery, sharp glints against the mud.

I’ll lark anywhere. If the river is high, I’ll turn to the hedgerows. If the hedgerows are fat and impenetrable with spring leaves, I’ll walk the lines of rapeseed and get covered in a dusting of neon yellow pollen.

My new field is a gem. It abuts the land of a big house – so big, I can only imagine it, as it’s hidden up a long drive and over a hill – and I think it must have been used as a dump for that house. Nearly everything I find it broken by a thousand plough blades, mixed up into history confetti.

There are archaeologists who sneer at mudlark finds because they’re so rarely found in their original place. They can’t be dated by their position in the strata of the land. This field is an archaeologist’s nightmare. And a mudlarker’s delight.

Shards of pottery and glass of all ages, patterns and classes. A porcelain gentleman’s arm. A bakelite comb with no teeth, pretending to be tortoiseshell. The head of a Chinese dragon. An enormous crop of bottle stoppers in every form: vulcanite screw tops, stoneware lids, aqua glass.

Mudlarks are magpies, not historians (though sometimes we pretend). Some have a period of particular interest but we are rubbish collectors above all and just as likely to value a Victorian shoe sole as an intaglio key fob.

‘Mudlark’ used to mean a no-good petty thief of the lowest order. Even in the days when it referred to the women and children who searched the river mud for spilled cargo, rope and loose coal, it whispered criminality. Mudlarking itself wasn’t illegal, but it was so looked down on as to be thought in some way immoral.

Descriptions of mudlarks often commented on their ragged and destitute appearance – and, of course, we must remember that they weren’t wallowing around in the rivers of today. Despite our government’s best efforts, our rivers are still a hundred times cleaner than the rivers of the Victorians. Mudlarks on the Thames were wading through sewage, toxic manufacturing chemicals, waste of every kind and even corpses. Society has always had a horror of the people who deal with a city’s waste problems, and Victorian London had a LOT of waste problems, from literally overflowing cemeteries to accelerating heavy industry with few safeguarding laws.

We focus on the Victorian mudlark because that’s where we got the cute word, but people have always scavenged and foraged. What I wonder is whether mine is the first century of larks who searched the mud simply for pleasure, rather than survival. There are bottle diggers and beachcombers who sell what they find, but only as a way to support their hobby and alleviate their storage problems.

In the mud, I’m at peace. I’m doing the opposite of hustling. But a mudlark 200 years ago would have been scampering before the tide, fighting the sucking clay and searching agonisingly for any nail, pin, wood or fuel that might buy their next meal. What an irony, that my relaxing little past time has evolved from the desperate, ceaseless fight against starvation.