[6][7] In the autumn of 1889 the architect embarked on a study tour of continental museums and art galleries to prepare himself for the task, an exhausting project which included visits to Bruges, Ghent, Antwerp, Amsterdam, Berlin, Frankfurt, Kassel and Dresden.

[11] The impressive pedimented entrance block is richly treated[12] with more portrait busts in roundels, which include that for the 5th Earl Stanhope (1805–1875) whose campaign in parliament had led to the NPG's foundation in 1856 (the Gallery first opened in a Georgian house in Great George Street, Westminster, in 1859).

[16] Here Christian was to remain for the rest of his life and during this time, in addition to his building and restoration work, produced thousands of reports on designs for Church of England buildings that were submitted to the Ecclesiastical Commissioners for approval,[16] completed surveys on the fabric of ancient churches including 14 cathedrals and assessed many architectural competitions, work which continued to within four days of his death at the age of 80.

[33][26] His Evangelical religion was deeply woven into his life; he regularly worshipped at St. John's Chapel, Downshire Hill, in Hampstead, and was for more than 35 years a Sunday School teacher and superintendent there.

The St Giles' Church, Skelton, is an example of the Early English style of Gothic architecture which Christian admired and was built about the year 1247, probably by the masons of York Minster's south transept.

[35] Christian gained some recognition from these achievements, particularly from supporters of the Gothic Revival in architecture, and he went on to win the competition for the restoration of St. Mary's Church, Scarborough in 1847 which he called "the cornerstone of success".

[2] The building of the pyramidal spires on the western towers (1881) restored a lost feature to the church: the originals had been destroyed in a fire of 1711 and Christian's work replaced flat roofs of 1802.

[46] The red brick tower Christian provided for Holy Trinity Church, Dalston (1878–79), in the London Borough of Hackney, is set high over the crossing and is reminiscent of the work of Samuel Sanders Teulon (1812–1873).

St Mark's is unusually faced in dark purple-grey slate from the quarries of the donor, William Perry Herrick (1794–1876), in Charnwood Forest, Leicestershire[51] The church displays a chancel apse, high roof and a tower topped by a Doulting limestone spire rising to 168 feet.

[53] Inside, St Mark's has stone arcading with polished pink Shap granite columns, capitals with carved foliage and striped polychrome arches.

[55] St Mark's southern and western boundaries were originally canted, so that the site narrowed from east to west and its length to decreasrf from south to north.

[42] Christian also worked in the Perpendicular Gothic style providing some very attractive Perpendicular traceried windows for the church of St James the Greater (1883), Oaks-in-Charnwood in Leicestershire, which was built in local granite and has a fine west tower,[62] and also for the church of St Dionis, Parsons Green in the London Borough of Hammersmith and Fulham, built in red brick with stone dressings in 1884–85, its tower completed after Christian's death in 1896.

[63] For the restoration of the ancient Church of St Laurence (1860) in Warkworth, Northumberland, Christian provided a lovely group of chancel east windows in the round-arched Norman style[64] and designed a Neo-Norman organ case for Romsey Abbey in Hampshire in 1858.

[65] In 1876–77 he added a Norman style family chapel and vestry to St Andrew's Church near Weston Park in Staffordshire to match the classical work of 1701 a little better than with Gothic.

[66] The composition of Minor Canonries (1878–1880) that Christian designed as residences for canons of St Paul's Cathedral, London in nearby Amen Court is in the manner of Norman Shaw's Domestic Revival architecture, inspired by original Elizabethan and Jacobean buildings.

Here Christian provided a careful design in red brick, beautifully set along the court, with large mullioned and transomed windows; patterned gables and tall chimneys; a tower topped by his usual pyramidal roof and elegant shell hoods over the doors.

[67] In a similar Elizabethan style is the bank (1884–1886) that Christian designed for Messrs Cox & Co, bankers to the army, in Whitehall, Westminster, though here the building is faced in stone.

Many were built in a heavy Tudor style with large stone mullioned and transomed windows, steep roofs with dormers and tall brick chimney stacks and displaying decorative timber-framing and tile-hanging.

)[77] The house is picturesquely designed in red brick and is set at an angle to the corner of the road with large stone mullioned windows and a tile-hung projecting bay.

[77] A very typical tower with its own pyramidal roof is placed asymmetrically at a corner of the building and there is a charming first-floor open trellis-work balcony which had views of the heath.

[79] Thwaitehead's design predominantly displays the influence of the Domestic Revival style of architecture made popular at that time through the work of Richard Norman Shaw (1831–1912)[77] and W. E. Nesfield (1835–1888).

[82] Christian's colossal work load required enormous amounts of energy to match it and despite having some bouts of serious illness as he got older the architect continued to meet the demands of his large practice.

[83] Typical of this is his appointment in 1887 as Consulting Architect to the Charity Commissioners for whom he produced a great report on the City of London churches which was said to be 'the most complete account [of them] ever written'.

[84] This contrasts with his rather insensitive restoration work of 1851 and 1866 to Nicholas Hawksmoor's Christ Church, Spitalfields in east London where he drastically removed the old galleries and box pews and made alterations to the original windows.

[20][86] In that for an Anglican Cathedral in Liverpool (1884–1886) his choice of Sir William Emerson's odd design of mixed styles for the building, which was to be built on a sensitive site close to St George's Hall, caused a controversy within the RIBA which was aired publicly in the press.

[90] Despite their arduous and careful work the committee experienced much hostility towards their choices and, having made the final selection, parliamentary economic concerns led to the collapse of the scheme (two separate buildings were later constructed), thus wasting the time and effort of Christian and his colleagues.

[91] Christian has rarely been regarded as a great genius in the architectural world, and his work has been much criticised since his death as being generally dull and lifeless and often lacking elegance and grace.

His concern for solid building was also an influence on his assessments for the Ecclesiastical Commissioners, as shown when he annoyed William Butterfield by insisting that the architect thicken the walls in his design of St John's Church (1876) at Clevedon, Somerset.

[100] Christian's employers no doubt expected him to carry out his restorations to a set standard which would include the removal of old box pews and galleries and the providing of new seating and furnishings, as in the architect's work at Christ Church, Spitalfields.

He scrupulously kept within his employers' budget and was always concerned to meet the client's needs and requirements for a commission, as is clearly shown in his work for W. H. Alexander on the National Portrait Gallery, London.