On the 10th of July 1212 the ‘Second Great Fire of London’ started. This fire is also known as ‘The Great Fire of Suthwark’. The fire began in Southwark the borough directly south of London Bridge. The flames destroyed Our Lady of the Canons (Southwark Cathedral, also known as St Mary Overie) and strong southerly winds pushed them towards the bridge, which also caught fire. London Bridge had only just been rebuilt in stone, and the structure itself survived the blaze. However, King John had authorised the construction of houses on the bridge, the rents from which were supposed to pay for its maintenance, and it appears that these were lost to the flames.
The earliest account of the blaze appears in the Liber de Antiquis Legibus, composed in 1274 and today the oldest book preserved among the records of the City of London Corporation. This states: “In this year was the Great Fire of Suthwark, and it burned the church of St Mary, as also the Bridge, with the chapel there, and the great part of the city.” According to later traditions, however, numerous casualties were incurred when a mass of citizens from London rushed onto the bridge at the first signs of fire, intending to cross the river to help extinguish the flames. High winds carried red-hot embers across the river and ignited buildings on the north side of the bridge. This fire trapped a large number of people, many of whom died either in the blaze or while attempting to escape on overloaded boats that had come to their aid.
Some estimates put the number of people killed on London Bridge alone at 3,000, but although this figure still appears in the Guinness Book of Records, it is not contemporary and is certainly an exaggeration; the total population of the whole city at this time was no more than 40,000 to 50,000 people. No reliable evidence survives to allow an accurate estimate of the number of casualties caused by the great fire of 1212, but it is known that the damage done to London Bridge was such that the structure remained a ruin, only partially usable, for years afterwards.