Swan Upping is the annual count of the mute swans on the River Thames. For five days in the third week of July, six wooden rowing skiffs led by the King's Swan Marker row upstream from Sunbury to Abingdon, stopping at every family of swans to lift out the cygnets, weigh them, measure them and check them for injury. It is free to watch from the riverbank, and the route and times are published in advance.
The custom goes back to the Middle Ages, when the Crown claimed the mute swans on open water as its own property, and swans were a luxury food served at royal feasts. Nobody eats them now, and the week has become a wildlife survey and a school outing as much as a ceremony. For a visitor it is one of the strangest and most charming things to see on the river: men in scarlet and white shirts rowing old skiffs flying royal and livery flags, and then, suddenly, the cry of "All up!" and a scramble to surround a swan family. Our overview of what is on in London in July puts it alongside the month's other events.
Swan Upping at a glance
- When
- Monday to Friday of the third week of July. In 2025 it ran from 14 to 18 July and in 2026 from 13 to 17 July (checked November 2026)
- Route
- Upstream on the non-tidal Thames, from Sunbury Lock, just outside the Greater London boundary, to Abingdon Bridge in Oxfordshire
- Boats
- Six traditional Thames rowing skiffs in three teams of two
- Led by
- The King's Swan Marker, with the Swan Markers of the Vintners' and Dyers' Companies
- Cost
- Free to watch from the towpath, locks and bridges
- Timetable
- Announced each summer by the King's Swan Marker, usually in June, with times at each lock and bridge
- Nearest to London
- Sunbury, about 47 minutes from Waterloo by train, two an hour (National Rail, checked November 2026)
Who owns the swans on the Thames
The legal position is the reason the event exists. According to the royal household, the Crown has held the right to claim ownership of all unmarked mute swans swimming in open water since the twelfth century. The Dyers' Company puts the date at around 1189, and says that an Act of Parliament of 1483 laid down that only the monarch could grant the possession of swans, and with it a swan mark.
Over the centuries the monarch granted those rights to many families and institutions, because swans were valuable. Almost all have lapsed. Today only three owners besides the Crown keep them: Abbotsbury Swannery in Dorset, granted its right in the fourteenth century, and two City of London livery companies, the Vintners and the Dyers, which have held theirs since the fifteenth century. The King exercises his right mainly on certain stretches of the Thames, and the Crown's claim today rests on the royal prerogative.
Ownership of a cygnet follows its parents. A cygnet whose parent belongs to the Vintners or the Dyers belongs to that company; the rest are Crown birds. The swans themselves are now a protected species, whoever owns them.
What actually happens on the water
There are three teams, each of two boats. The Dyers' Company describes them like this: the King's men wear red and are commanded by the King's Swan Marker; the Vintners wear white under their own Swan Marker; and the Dyers wear blue under their Barge Master. Each boat flies either the royal standard or the company flag. All the rowers are Thames watermen, and many are the sons and grandsons of earlier Swan Uppers. The King's Swan Marker, the one in charge of the whole flotilla, wears a cap with a white swan's feather.
The boats move steadily upstream, rowing between locks. When someone spots a pair of adult swans with cygnets, the call goes up, "All up!", and the skiffs manoeuvre to surround the family against the bank. The birds are lifted out of the water, and the cygnets are weighed and measured to estimate how fast they are growing, then examined for disease or injury. The most common injuries come from fishing hooks and discarded line.
The King's Swan Warden, whose role is scientific rather than ceremonial, travels with the flotilla, and representatives from the Swan Sanctuary are on hand to take in any bird that needs treatment. Then the swans are released and the boats row on. A single family can take ten minutes or more, which is why the published timetable has generous gaps.
Marks are rings now, and the King's birds carry none. The old marks were nicks cut in the beak: two for the Vintners, one for the Dyers, and none for the Crown. Beak-marking stopped in the early twentieth century. Cygnets are now ringed on the leg with individual numbers and recorded, and the royal household notes that Crown birds are still left unmarked, as they always were.
The timetable: how a typical week runs
The exact times change each year with the river and the swans, and the King's Swan Marker publishes them before the week begins. The pattern has been steady for years: the first day starts at Sunbury and ends around Windsor, the middle days work up through Maidenhead, Marlow, Henley and Reading, and the last day finishes at Abingdon on the Friday.
The 2025 timetable, published by the Swan Marker and reported in the Henley Standard, shows how detailed the schedule is. It is given here as an example of the pattern, not as a forecast for any later year.
| Day (2025) | Stops and published times |
|---|---|
| Monday 14 July | Start at the Sunbury Lock cut; end of day at Romney Lock, Windsor, 5.30pm |
| Tuesday 15 July | Eton Bridge 8.30am, Boveney Lock 9.15am, Boulters Lock 12.30pm, Cookham Bridge 1.30pm, Marlow Lock 5.30pm |
| Wednesday 16 July | Marlow Bridge 9am, Hurley Lock 10.30am, Hambleden Lock noon, Henley town 1.15pm, Marsh Lock 3.30pm, Shiplake Lock 5pm, Sonning Bridge 6pm |
| Thursday 17 and Friday 18 July | Upstream from Sonning to Abingdon Bridge, finishing on the Friday |
Treat every published time as approximate. If the crews find a lot of swans in the morning, they fall behind; on a stretch with few birds they can arrive early. Be in place at least half an hour before the listed time, and expect to wait.
The best places to stand
Locks and bridges are the best places, for two reasons. The boats have to slow down or stop at a lock, so you get a long look at them, and locks have public footpaths and railings along the edge. A bridge gives you the view down onto the skiffs as they pass under it.
Sunbury is the easiest from central London and the place to see the start on the Monday. Trains run from Waterloo to Sunbury station twice an hour and take about 47 minutes; the lock is a walk from there, and you should allow time to find it on the map.
Windsor and Eton are the best compromise for most visitors, because there is plenty to do while you wait. The boats usually reach the Windsor stretch late on the first day and leave from Eton early on the second. Our guide to the train from London to Windsor compares the two routes, and Windsor in half a day shows how to fit the castle around a morning on the riverbank.
Henley-on-Thames is the prettiest place to watch. The flotilla usually passes through the town around lunchtime on the third day, and the Henley stretch has a long, open towpath. Our page on Henley and Marlow covers the train and the walk between the two towns, which follows exactly the stretch the swan boats row.
The towpath is the free grandstand. The whole route follows the Thames Path, so you can walk with the boats for a mile or two between locks. They row at walking pace or a little faster, and you will often keep up. Our page on the Thames Path has the route and the sections within reach of London.
The count, and why the numbers matter
After the week the King's Swan Marker produces a report on the number of swans, broods and cygnets counted. The figures have been worrying. In 2024 only 86 cygnets were found, a fall of 45 per cent in two years, as the Henley Standard reported. Announcing the 2025 week, the Swan Marker put the downturn down mainly to outbreaks of avian influenza among British birds, and noted that reported cases on the Thames had fallen.
The count has helped before. When numbers fell sharply in the 1970s, the late Queen and the two companies commissioned an investigation which found that swans were being poisoned by swallowing lead fishing weights. Lead weights were banned, and numbers recovered. Today the Swan Marker's main concerns, according to the royal household and the Dyers, are discarded fishing tackle, uncontrolled dogs near nests, vandalism, predators such as mink, and the loss of reed beds along concreted banks.
That is the reason the week now spends so much time with schoolchildren. Pupils from primary schools along the route meet the Swan Uppers at several stops for a question-and-answer session and see cygnets close up. If you arrive at a lock and find a crowd of children in high-visibility jackets, you have come to the right place.
Why it is not in central London any more
In earlier centuries Swan Upping began at London Bridge. Today it covers only the non-tidal river above Sunbury, because that is where the swans breed. There is nothing to see on the Thames through central London, and nothing at Westminster or Tower Bridge. If you want a river event in the city itself, the Totally Thames festival in September is the one; Swan Upping requires a train out to the suburbs or to Berkshire.
The closest stretch to London is the reach between Sunbury and Windsor, past Staines and Runnymede. Nearer still, the river at Teddington and Hampton is just downstream of the start, and makes a good riverside day even outside Swan Upping week. The tidal river, from Teddington Lock to the sea, is managed by the Port of London Authority rather than the Environment Agency, which is one reason the two halves of the Thames feel so different.
Watching politely
The Swan Uppers are working, and the birds are wild. Stay on the bank, keep dogs on a short lead, and do not try to feed or touch the cygnets when they are lifted out. Photographs are fine from the bank; the crews are used to cameras.
The livery companies themselves are part of the City of London's older life. The Vintners' Hall and Dyers' Hall are both in the City, and our guide to the livery halls and when they open explains which of these private buildings you can get into. For another living London custom with a long history and no admission charge, see the pearly kings and queens' harvest festival in September.
Frequently asked questions
When is Swan Upping?
Swan Upping takes place over five days, Monday to Friday, in the third week of July. In 2026 it ran from 13 to 17 July. The King's Swan Marker announces each year's dates and times in advance, usually in June, and they are reported in the local newspapers along the route.
Can you watch Swan Upping in London?
Not in central London. The route runs from Sunbury, just beyond the south-western edge of Greater London, upstream to Abingdon in Oxfordshire. Sunbury is about 47 minutes by train from Waterloo, and Windsor, Marlow and Henley are all within an hour of Paddington.
Does the King own all the swans in Britain?
No. The Crown has the right to claim unmarked mute swans on open water, and exercises it mainly on certain stretches of the Thames. Some swans belong to the Vintners' and Dyers' Companies and to Abbotsbury Swannery, and other species of swan are not covered at all.
What happens to the cygnets during Swan Upping?
They are lifted briefly out of the water, weighed and measured, checked for injury and disease, and ringed with individual numbers, then put back with their parents. Injured birds can be taken into care by the swan charities that travel with the boats.
Is Swan Upping free to watch?
Yes. There are no tickets and no viewing areas to book. You stand on the public towpath, at a lock or on a bridge and wait for the skiffs to come past at the published time.
Sources
- The Royal Family - Swan Upping (checked November 2026)
- The Dyers' Company - Swan Upping (checked November 2026)
- Henley Standard - Historic Swan Upping returns to River Thames next month (2025 timetable) (checked November 2026)
- Euronews - King's Swan Upping on the Thames, July 2026 (checked November 2026)
- National Rail Enquiries - London Waterloo to Sunbury, times (checked November 2026)