Traditionally, sellers of the same product were clustered on one street, a practice which is remembered in some of the street names running off Cheapside.
Through the middle ages, Cheapside was the Oxford Street of its day (and was much wider - it was narrowed during the 19th century), the city's retail centre, shopped by rich and poor. Nothing remains of the shops that once lined the street, apart from a lone 17th-century survival on the corner of Wood Street - 124-126 Cheapside.
The corner shop has shop front fittings dating from 1902, when the row was shortened during the widening of Wood Street. The shops' narrowness (see below) is due to the proximity of St Peter's Churchyard behind - on the site of St Peter Cheap, which burned down in the Great Fire. The tree behind the shops marks the site of the church and old records show that later leases on these shops forbid the addition of an extra storey or removal of the tree.
The tree achieved a measure of fame - Wordsworth mentioned it in a poem, The Reverie of Poor Susan. A verse from the poem is on a sign nearby.
Walter Thornbury in 1878 said the tree "has cheered many a weary businessman with memories of fresh green fields far away", and was nested by rooks in the 19th century until the birds decided the City was no longer a desirable residence.
Here is an undated illustration of the tree and the shops, which looks 19th century. There are four shops rather than the three that stand there today, but otherwise it's remarkably similar. And maybe those are the rooks up there in those nests...
Shopping shifted to the West End in the 19th century, meaning Cheapside lost its retail prestige and became a street of offices. However, the opening of shopping centre One New Change has at least put it back on the retail map, and it's apt that One New Change sits directly opposite the street's only retail relics.