This unusual building in fact incorporates three sacred precincts: The Temple of the legendary Athenian King Ericthonius, from which the structure derives its name, the 'Erechtheion' (it is also sometimes called the Temple of Poseidon Erectheus), the Temple of Athena Polias, and the famous Caryatid Porch (also sometimes known as the Sanctuary of Pandrossus). It is also built over two levels and this, together with the need to incorporate three sacred areas, accounts for the building’s irregular plan.

The present structure dates to 421-405 BC and is the work of the Greek architect Mnesikles, who also built the Propylaea (see model MR21). Constructed using Pentelic marble, it incorporates the main eastern Ionic porch of the Temple of Ericthonuis. At the western end is the Temple of Athena Polias (referred to by Soane, using the Roman name of the Goddess, as 'Minerva Polias' - she was the protectress of the city of Athens) which, along with the Caryatid Porch, was accessed through another ionic porch on the north side of similar form but at a lower level to the eastern porch.

Although Le Roy’s Les ruines des plus beaux monuments de la Grèce, reproduces the Erectheion it appears that in this instance Fouquet has turned to an English source: plates III-XX, chapter II, Vol. II of James Stuart and Nicholas Revett’s The Antiquities of Athens. The very linear style used in these plates closely resembles the linear and very precise nature of Fouquet’s model. Fouquet also follows the ‘geometrical’ way in which Stuart and Revett depict the terrain on which the Erectheion is built. Rather than show a gentle slope, as does Le Roy, they depict a series of defined terraces to represent the change in level of this part of the Acropolis.

Sir John Soane purchased the twenty models by François Fouquet in 1834 from the architect Edward Cresy (1792-1858) who, from 1829 to 1835, worked in Paris. Soane paid Cresy the substantial sum of £100 (£10,136.78 in today’s money). It is likely that Cresy purchased the models directly from Fouquet et Fils.

Wonders of the Ancient World: François Fouquet's Model Masterpieces, Sir John Soane's Museum, London, 15 July - 22 November 2011