St Mary's Church is in the village of Eccleston, Cheshire, England, on the estate of the Duke of Westminster south of Chester.

There is also a large brass plaque listing those members of the Grosvenor family who were buried in the vault once part of Porden's old church.

Their resting place in the northeast part of the Old Churchyard is now marked with a simple memorial and surrounded by a low wall with crosses in the corners.

[9] Separating the Grosvenor Chapel from the church's chancel is a monument to the memory of the 1st Duke of Westminster dated 1901, which consists of a tomb-chest and canopy designed by Bodley with an effigy by Farmer and Brindley, sculpted by Léon-Joseph Chavalliaud.

The authors of the Buildings of England series were impressed by the furnishings of the church, in particular the reredoses by Farmer and Brindley, the chancel screens, the organ case and the bench ends.

[7] Along the south side of the remaining wall of Porden's old church are the graves of the Dukes of Westminster, other members of the Grosvenor family and their relatives.

A square enclosure in the northeast part of the Old Churchyard, now covered with gravel and surrounded by a low wall with crosses in the corners, marks the spot where the Grosvenor family vault was located within Porden's church.

The names of those ancestors of the Dukes of Westminster who are interred here are recorded on a brass plaque inside the present church building.

The gravestone of Edward George Hugh, Earl Grosvenor (1904–1909), by Detmar Blow and Fernand Billerey, sculpted by Emile Madeline, is a Grade II listed building.

[14] Many ancestors of the Dukes of Westminster, including: A stone tablet in the enclosure (see here) bears the arms of the Grosvenor baronets with the dates 1599 and 1894 and the inscription: "This stone marks the resting place of those members of the Grosvenor family who were buried in a vault under the old church which was demolished in 1900 and who were reinterred in this plot and their names are recorded on the memorial tablet in Eccleston church."

As the inscription indicates, the names of those family members buried here are listed on a large brass wall plaque in the north aisle of the church (see here).