Privately educated with an MSc in contemporary urbanism from the London School of Economics, Trenton Oldfield makes an unlikely agitator against elite society.

His achievements also include becoming a fellow of the Royal Society of Arts and working for non-governmental organisations specialising in regeneration programmes.

However, the self-proclaimed activist turned his back on his connections to high society when he swam into the path of the Oxford and Cambridge rowing crews, causing the race to be suspended for the first time in 11 years. The oars of both crews skimmed past him as he ducked under the water.

Wearing a wet-suit and with a smile on his face, the 35-year-old protester was hoisted on to the umpire's boat, handcuffed and arrested by river police. Last night he was charged with a public order offence and released on bail to appear before magistrates on 23 April.

Cambridge eventually won the restarted race but that seemed like a minor detail after the most bizarre series of events in the competition's history. The drama continued as Oxford rower Alex Woods collapsed at the finish line after the race had restarted. He received 30 minutes of treatment from paramedics before being taken to Charing Cross hospital, where his condition was described as stable.

Oldfield's plunge into the Thames drew condemnation from Karl Hudspith, president of the Oxford University Boat Club. Hudspith wrote on Twitter: "To Trenton Oldfiled (sic); my team went through seven months of hell, this was the culmination of our careers and you took it from us."

Oldfield's LinkedIn profile says he helped set up This is Not a Gateway, a non-profit organisation that "creates platforms for critical projects and ideas related to cities".

He describes himself as "rich, open-minded, multidisciplinary, efficient, focused, intelligent, honest, unique". Oldfield is listed as having worked in project management roles for various charities and non-governmental organisations, including as a co-ordinator of a project to regenerate the Thames between Kew and Chelsea.

In many ways, Oldfield makes a perfect candidate to join the upper echelons of society whose day out at the Thames he rudely disrupted.

Somewhere along the way, however, he appears to have developed a grudge. On a blog entitled Elitism Leads to Tyranny, he uses a 2,000-word manifesto to justify the use of "guerrilla tactics" to disrupt the event, citing the stretch of river as a heartland of establishment power. He writes: "This is a protest, an act of civil disobedience, a methodology of refusing and resistance." Oldfield's blog dismisses the Boat Race as a "pseudo competition" that allows the elites to "reboot their shared culture in the public realm".

"Most standing alongside the Thames today are in fact the pumped-up though obedient administrators, managers, promoters, politicians and enforcers; functional, strategic and aspirational elites," he writes. "The transnational-corpo-aristocratic ruling class (invisible) haven't turned up today and would never consider doing so, despite the best endeavours of Bollinger, Xchange and Hammersmith & Fulham's mayor."

Oldfield also sets out his doctrine of guerrilla tactics, citing his inspiration as suffragette Emily Davison, who died after throwing herself in front of the king's horse at Epsom Derby in 1913.

"My swim into the pathway of the two boats today (I hope) is a result of key guerrilla tactics; local knowledge, ambush, surprise, mobility and speed, detailed information and decisiveness," he writes. "There is no choice but to be apprehended in this action. I know this area very well and have planned the swim as best as I can, taking into account all the local knowledge I have gained."

Oldfield's doctrine finishes with a series of bullet points encouraging acts of civil disobedience, including workers setting off fire alarms in their offices and plumbers sabotaging Conservative thinktanks. He asks: "If you have a tow truck company, can you park in front of Nick Clegg or David Cameron's driveway, accidentaly? (sic) Could you tow their car away?" The blog ends: "This is a special call to security guards. The elite depend on you the most. Without you they are nothing."

Oldfield's blog

Edited extracts

This is a protest, an act of civil disobedience, a methodology of refusing and resistance. This act has employed guerrilla tactics. I am swimming into the boats in the hope I can stop them from completing the race and proposing the return of surprise tactics. This is 'peaceful'… I have no weapons (don't shoot!). My only fear is not swimming fast enough to get in the right position.

This part of the Thames is the site of a number of elitist establishments – Fulham Palace, Chiswick House and St Paul's Schools – and a large collection of other 'independent/public/free schools'. It is also where Nick Clegg lives with his family, despite his constituents living hundreds of miles away in post-industrial Sheffield.

Most notably, and most importantly for today, it is a site where elitists and those with elitist sympathies have come together for the past 158 years to perform, in the most public way, their ambition for the structures and subsequent benefits from elitism and privilege to continue. (They even list in the programme which public school the rowers attended before Oxford or Cambridge).

The Boat Race itself, with its pseudo competition, assembled around similar principles of fastest, strongest, selected … etc, is an inconsequential backdrop for these elite educational institutions to demonstrate themselves and reboot their shared culture together in the public realm.

My swim into the pathway of the two boats today (I hope) is a result of key guerrilla tactics; local knowledge, ambush, surprise, mobility and speed, detailed information and decisiveness.