On a site east of Tower Hill, Edward III founded the Cistercian abbey of St Mary Graces in 1350. Gardens and open lands to the abbey’s east included a square field of about ten acres known as Well Close.

Wellclose Square was part of the ancient parish of Stepney. This was later divided into Whitechapel (by 1329), Wapping (1694) and St George in the East (1729). The boundaries of these parishes met in Wellclose Square.

Daniel Defoe mentions Wellclose Square is his "A tour thro’ the Whole Island of Great Britain" (1724). He says that there used to be a well in the centre of the square which was also known as Goodman’s Field’s Well.

In 1682, Nicholas Barbon leased the Liberty of Wellclose (or Well Close) from the Crown and intended to attract richer members of the local maritime community to his new Wellclose development - to be renamed ’Marine Square’.

New roads north and south, initially Little Cable Street and Neptune Street, linked to Cable Street, and Ratcliff Highway, renamed Parsons Street.

Scandinavians were particularly attracted to the area and Danish king Christian V gave funds for the construction of a new Danish Church on the square. The architect was the Danish sculptor Caius Gabriel Cibber and the church was completed in 1696. Nos 20 & 21 on the west side later housed the Danish Embassy.

Wellclose Square inspired a Swedish community to take root in nearby Princes Square (later renamed Swedenborg Square).

Many houses had been built round the square by the late 1690s, but development was slow, something that was commented on and worried about. The name Marine Square was used through the early decades, but Wellclose Square was in common usage by 1717 and universal by about 1750.

As the nineteenth century dawned, the gradual industrialisation of the East End saw a social decline set in. The number of pubs, lodging houses, pawn shops, and music halls increased. Sugar refineries with a mainly German workforce moved in locally.

Amid the sugar refining and coopers’ businesses, Gunner Alley was known as Harwood Court by the 1740s, later Harold’s Alley, then from 1895 Harad’s Place. It was redeveloped with Well Court inserted to its south in the late 1780s. Charles Court was added off the north side in the early nineteenth century. Little Cable Street became Shorter Street in the eighteenth century then Fletcher Street from 1939, and Anchor Alley was redesignated North-East Passage. Neptune Street became Wellclose Street in 1938.

There were shops on the square by the 1830s, and many houses and their gardens came to host small-scale manufacturing. By 1840 the address had lost any middle-class desirability, despite the large houses.

Wellclose Square attracted a number of charitable institutions, starting with the Sailors’ Orphan Asylum by the 1830s and the Emanuel Almshouses replaced a sugarhouse in 1848.

A number of Wellclose Square’s late seventeenth-century houses survived into the 1960s.

The centre of the square is now occupied by St Paul’s Whitechapel Church of England Primary School and on the western edge is another primary school.