Four-centred arch

The four-centered arch is widely used in Islamic architecture, originally employed by the Abbasids and later by the Fatimids and by Persianate cultures. The earliest examples of a four-centered arch were introduced at Samarra, a purpose-built capital built by the Abbasids in the 9th century. Here they are found in the portals of the Qubbat al-Sulaiybiyya, an octagonal pavilion, and the Qasr al-'Ashiq palace. In this Persianate cultural sphere it was used for forms such as arcades, windows, gateways, and iwans. It is distinguished from other four-centered arches by having most of the arch's normal radius appear more straight than curved. File:West Gate.jpg|The 16th century western gate of the Purana Qil'a fortress, Delhi. File:Inside Jama Masjid, Bijapur, Karnataka.jpg|The 16th century Jama Mosque in Bijapur with rib vaulting consisting of four-centred arches. File:Agra Fort 20180908 141819.jpg|The 16th century Jahangiri Mahal at the Agra Fort has a four-centred arched gateway flanked by four-centred blind arches. File:One of the seven wonders.jpg|The 17th century Taj Mahal mausoleum of Mumtaz Mahal in Agra. File:সুউচ্চ তোরণ!.jpg|The 17th century south-eastern gateway of the Lalbagh Fort in Dhakkar. File:Bara Kaman (19574932503).jpg|The 17th century Bara Kaman mausoleum of Ali Adil Shah II in Bijapur. ==Use in English architecture==

In English architecture, the Tudor arch is a version of the four-centred arch that was a common architectural element during the reigns of the Tudor dynasty (1485–1603), though its use predates 1485 by several decades, and from about 1550 it was out of fashion for grand buildings. It is a blunted version of the pointed arch of Gothic architecture, of which Tudor architecture is the last phase in England. A Tudor arch differs slightly from a true four-centred arch in having two straight sides instead of large shallow curves. The Tudor arch was especially used for doorways, where it gives a wide opening without taking too much space above, compared to a more pointed two-centred arch. This first appeared on a major scale in the west porch of Winchester Cathedral, of uncertain date but likely mid-fourteenth century. In Tudor architecture of the grander sort it is so used when the window openings are rectangular, as for example at Hampton Court Palace. A notable early example is the west window of Gloucester Cathedral. There are three royal chapels and one chapel-like Abbey which show the style at its most elaborate: King's College Chapel, Cambridge; St George's Chapel, Windsor; Henry VII's Chapel at Westminster Abbey, and Bath Abbey. However, numerous simpler buildings, especially churches built during the wool boom in East Anglia and the Cotswolds, also demonstrate the style. When employed to frame a large church window, it lends itself to very wide spaces, decoratively filled with many narrow vertical mullions and horizontal transoms. The overall effect produces a grid-like appearance of regular, delicate, rectangular forms with an emphasis on the perpendicular, characteristic of the style, known as Perpendicular Gothic in England, of the 15th and early 16th centuries. This is very similar to contemporary Spanish style in particular. In buildings such as Hampton Court the Tudor arch is found together with the first appearance of Renaissance architecture in England, much later than in Italy. In the later period it is generally only used for major decorative windows, perhaps in an oriel window, or a bay window supported on a bracket or corbel. File:Gloucester Cathedral Front.jpg|Gloucester Cathedral, west window, c. 1420 File:Kings College Chapel Cambridge.JPG|King's College Chapel, Cambridge, begun 1446 File:Great Gate, Trinity College, Cambridge (inside).jpg|Great Gate, Trinity College, Cambridge (inside), 1519–35 File:Hampton Court Palace. - panoramio (3).jpg|Clock Court gatehouse, Hampton Court Palace, c. 1520 File:St Georges Chapel Windsor Castle.jpg|St. George's Chapel, Windsor, east window, 1475–1528 File:Bricked up door - geograph.org.uk - 1650083.jpg|Small doorway, now blocked, in a church ==Notes==