The Great Fire of London which occurred on September 2nd 1666 has had  a monumental impact on the structure and development of the city. Fire is said to have started in the bakery of Thomas Farriner's bakery shop on pudding lane, It is estimated that sparks from the oven may have set fuel ablaze. The first sightings are reported around 3 am. What was significant is how quickly the fire spread and the amount of damage done in a short time. Most of the dwellings were traditionally built of wood up until this time. Many buildings had upper stories jutting out to nearly touch their neighbouring houses across roads and alleys. Furthermore the country was suffering from a long drought all through that summer.. The flames were fanned by strong easterly winds that night. So the old buildings went up like a bonfire and spread like wild fire.

There were no fire brigades at this time. So action depended on local citizens organising themselves with leather buckets from the nearest well or stream. It was useless against this holocaust. The Lord Mayor of London, Sir Thomas Bloodworth, was later criticised for delays in taking action against the fire, in particular the felling of houses to create of fire breaks. The blaze was allowed to reach the docks where stores of oil, tallow and pitch added substantially to its fuel. Ultimately the fire was overcome by a combination of falling winds and soldiers using gunpowder to blow up buildings and create such a firebreak.

The result of the fire was immense. 

Around 100,000 people were made homeless

Roughly 13,000 homes were destroyed as were 87 churches.

The original St Pauls Cathedral and the Guildhall were destroyed.

The consequences of the fire were significant.

•   Parliament passed the Rebuilding Act of 1667 which determined that buildings should in future be built of stone or brick and should not be built so closely.

• Sir Christopher Wren, the country's foremost architect was commissioned to rebuild 51 churches that had been destroyed including St Pauls Cathedral that has stands as such a landmark to this day.

• A 202 foot (61m) Doric column, designed by Wren and Robert Hooke, was erected on Pudding Lane to commemorate the event. 

For a long time until at least the events of the feature length film The Great Fire of Pontypandy, the titular protagonist of the Welsh animated show and franchise, Fireman Sam had the catchphrase of “Great Fires of London!” although in the US dub of the programme, he instead says the more location neutral “Great fiery chimneys!” It seems like after experiencing something similar in his hometown to the very fire he used to name drop was enough to put him off from saying it ever again.