The east window, representing the Te Deum with Christ enthroned, is a good example of the work of Clayton and Bell and was added in 1879. The three lights on the north side of the chancel, also by Clayton and Bell and dating from 1874, formed the original east window, and were moved to the present position to make way for the new much larger window in 1979.

The reredos (wall behind the alter) of Caen stone arcading, includes in the intricate carving of the capitals and adjacent spandrels the instruments of the Passion. In the niches above are the figures of St. Mark, King David, Moses and St. John the Baptist carved from Chellaston alabaster by J. Underwood. The fresco panels are by Edward Armitage, R.A., and represent Christ the Saviour flanked by ‘Feeding the Hungry’, ‘Clothing the Naked’, ‘Taking in the Stranger’ and ‘Visiting the Sick’.

The North wall of the Sanctuary includes a fine example of polychrome marble mosaic in the back panel of the Credence shelf, while the clergy seats on the facing south side are of marble under three arches with miniature vaulting inside. The capitals and spandrels are well carved with fruits.

The floor of the Chancel, of marble tile pattering, is an exceptional example of its kind, and is centred on the Lion of St. Mark.

The roof of the Chancel and Sanctuary is splendidly painted with florets and angels, and the lower part of the former organ case is finely painted in the style of the period with angel musicians and stylised flowers. The original of 1847 was in the gallery, but in 1878 was enlarged by Walker and moved to the Chancel at the time of its enlargement. It was returned to its original position in 1958.

The massive Clergy Stall, of Caen stone with granite columns, was presented by the vicar, Canon Robinson Duckworth, whose portrait is seen at the west end of the Church, in 1878.

The Chapel in the Northeast corner includes the War Memorials panels brought in 1920 from St. Stephen’s Church, Avenue Road. The panels, painted by Sigismund Goetze, R.A., show Christ in Glory with musicians, and flanking panels of SS. George, Andrew, Patrick and David, with figures representing the Services below. The stained glass windows of St. Luke and St. Cecilia, by Leonard Walker, were added as the Goetze Memorial by the family and friends, for Goetze had always been closely associated with St. Mark’s.

1. The memorial mosaic in the three panels for the well loved curate, the Reverend Charles Erakine, who died of consumption in 1908, was designed by Sigismund Goetze and is a remarkable example of the period, including as it does much coloured and reflective shell.

2. The mosaic panel of St. Cecilia, patron saint of music, was added in 1938.

The Font, given in 1877, was originally at the west end of the Church, but was moved to the Baptistery when it was added in 1912, and then to its present position in 1968.

The mosaics along the south wall were mainly prepared by the Salviati and Company of Venice under the direction of J. Underwood and Sons of Baker Street, who installed them in the alabastor frames.