Usually when we try to find out the smallest/oldest/tallest example of a particular thing in London, we come back at you with 10 different answers. This time there's one universally agreed upon smallest church in London. Except it's not really used as a church anymore... so once again we have a few different answers. Sorry.
Located on Bishopsgate, St Ethelburga's is not only the smallest church in London, but also one of the oldest. Parts of the church were built in the 13th century, but most of the building dates back to the 15th. Back when it was built, it was the tallest building on Bishopsgate. It's now dwarfed by virtually everything around it.
For many years the church led a charmed life, being one of the few buildings in the City to survive the great fire unscathed. Similarly it suffered relatively little damage during the Blitz. In fact, the main reductions it suffered during this period were when the shop on its front porch (set up to raise funds for the parish) was removed as part of a road-widening scheme.
Its luck ran out; the church was badly damaged in 1993 by an IRA bomb and St Ethelburga-the-Virgin's future was left in doubt. The church had been officially deemed redundant about two years before the bombing, due to its size. But many in the public wanted it rebuilt as an act of defiance. A solution was finally reached upon: the church is now St Ethelburga's Centre for Reconciliation and Peace.
So. St Ethelburga's is definitely the smallest church in London — it's just no longer functioning as a church. And so our quest continued...
Our hunt was made especially difficult because London consists of more than one diocese. It's actually made up of three: Diocese of London (which is really just north of the river), Diocese of Southwark (south of the river) and Diocese of Chelmsford (which takes a chunk of east London). However, these only cover Church of England churches. So we put on our Sherlock Holmes deerstalker, and got back to it.
You might look at the above photo of St Hugh's in Bermondsey (taken during its construction in 2013) and scoff at the idea of it being small. Well, St Hugh's is only the bottom floor of that building. The Diocese of Southwark claims this is its smallest church — so tiny that not even the great Wikipedia recognises it.
St Hugh's used to be in the basement of the Charterhouse Mission settlement and served the people of West Bermondsey since 1896. When the building was deemed no longer fit for purpose in 2009, it was sold. Due to ecclesiastical law, the church had to be replaced, which led to the creation of the new St Hugh's.
Out in Northolt lies St Mary's. It's believed that there's been a church on the site ever since 1086 — just after the Normans conquered England. From reading into their records, it becomes evident that the church used to be even smaller than it is now. That's indicated by the many additions and renovations it's undergone throughout its history. They didn't even add the bell tower till the 18th century.
The parish is now St Mary with St Richard — St Richard's is a 10 minute walk down the road — presumably because St Mary's was too small to function on its own. St Mary's still opens regularly for services; if you're in the area, pop in. But maybe don't bring too many people with you.
An interesting option for London's smallest church, because it's neither C of E nor Catholic; St Sarkis is an Armenian church. It opened in 1923 as a home for the burgeoning British Armenian community, which had traditionally been based in Manchester. The church is rather stunning, sitting cosily on the corner of Iverna Gardens in South Kensington.
It was designed by Arthur J Davis and Charles Mewes, who are most famous for their work on The Ritz in Piccadilly. The two projects have a slight scale difference when put side by side. But what St Sarkis lacks in size it makes up for in religious razzle-dazzle.