Squinch

Squinch (pronounced skwinch)

(1) In architecture, a small arch, corbeling, or the like, built across the interior angle between two walls, as in a square tower for supporting the side of a superimposed octagonal spire or generally to support any superstructure such as a spire or dome.  Also called a squinch arch.

(2) To contort (the features) or squint (now rare).

(3) To squeeze together or crouch down, as to fit into a smaller space (now rare).

1490–1500: A variant of the obsolete scunch, short for scuncheon, from the Middle English sconch(e)on from the middle Middle French escoinson (The reveal of an aperture (such as a door or window) from the frame to the inner face of the wall) & esconchon.  Escoinson is drawn from its original formation es- & ex- (both from the Latin ex (out of, from)) + coin (corner).  The meaning in the sense of a squinting of the eyes emerged during the 1830s, the origin uncertain but likely an imperfect echoic.

The Hagia Sofia

Built by Byzantine Emperor Justinian I between 532 and 537 AD, the Hagia Sophia ((from the Greek `Αγία Σοφία (Holy Wisdom), Sancta Sophia or Sancta Sapientia in Latin)) sits at what has often been the strategically important point on the Bosporus between the Black Sea and the Mediterranean, long thought the boundary between Europe and Asia.

The four minarets were added at different times after 1453.  Thought aesthetically successful, they add also to structural integrity.

The Hagia Sophia was originally a Greek Orthodox Christian patriarchal cathedral in Constantinople (modern day Istanbul, Turkey), consecrated briefly as a Catholic church in the thirteenth century.  Noted for its vast dome, it was an extraordinary achievement of engineering, architecture and mathematics, for centuries the biggest building on Earth, remaining the largest cathedral for nearly a thousand years until the dedication in 1520 of the basilica in Seville.  In 1453, when Constantinople fell to the Ottomans, it became a mosque, remaining one until 1935, when, as part of the modernity project that was the Turkish Republic created by Mustafa Kemal Atatürk (1881–1938; (President of the Republic of Turkey 1923-1938)), it was made a museum, later becoming one of the country’s most popular tourist attractions.

Hagia Sofia dome with four (corner) squinch arches with supporting pendentives.

The pendentive is the construction element which permits a dome to be placed over a square or rectangular space.  Pendentives are triangular segments of a sphere that spread at the top, tapering to points at the bottom, thereby enabling the continuous circular or elliptical base needed to support the dome.  The horizontal curve of the dome’s base is connected directly to the vertical curves of the four supporting arches on each corner. Where the curve of the pendentive and dome is continuous, the vaulting form is known as a pendentive dome. 

Pendentives receive the outward force from the dome’s weight, concentrating it at the four corners from where it's transferred down the columns to the foundations below.  Before there were, pendentives, domes needed either the supporting structure to be round (The Pantheon) or were supported by corbelling or the use of squinches allowing the dome to sit on top of four arches.  Both methods imposed limitations of width and height whereas pendatives, which directed forces away from the walls, made possible bigger structures.  Invented in Ancient Rome, Byzantine architects perfected the technique and they came to be seen too in Islamic, Renaissance and Baroque architecture.

From the late twentieth century, religious sentiment in the secular state became more combative and by the early 2000s, demands were being heard from both the Christian Orthodox and Sunni Islam for the Hagia Sofia to again be a place of worship.  Political sentiments hardened and, in July 2020, on the very same day a court annulled the 1934 law which enabled the site to become a museum, Turkish president Recep Tayyip Erdoğan (b 1954; prime minister of Turkey 2003-2014 & president since 2014) signed a presidential decree under which the museum reverted to being the Great Mosque of Ayasofya.  Mr Erdoğan had flagged his intentions and the move was no surprise, this the fourth Byzantine church converted from museum to mosque during his time in office.  Architectural repurposing is hardly unknown west of the Bosporus either, thousands of mosques in Spain and Greece having over the centuries been converted to Christian churches.

The court’s rationale for annulling the 1934 decree was interesting, the judges finding it unconstitutional, under not only the contemporary Turkish constitution but also Ottoman law.  The court held that Mehmed II (1432-1481, محمد ثانى‎ in Ottoman Turkish, romanized as Meḥmed-i sānī), who conquered Constantinople in 1453, gained the Hagia Sofia as his personal property and, by the creation of a waqf (In the Arabic وَقْف‎ (ˈwɑqf), also known as a hubous (حُبوس); an inalienable charitable endowment of property under the Hanafi (Sunni law)), had lawfully made the structure permanently a mosque and thus unable to be used for any other purpose.  Under the Hanafi, Mehmed’s waqf was held to be valid, as was his gaining personal ownership in 1453 by virtue of the war code of the time.