DGA643504: France, Chateau d' Amboise, Loire Valley, guardroom of gothic, (UNESCO World Heritage List, 2000) / Bridgeman Images

DGA649937: View of octagonal holy water belfry and clock tower, Cluny Abbey, Cluny, Burgundy, France, 11th-12th century / Bridgeman Images

DGA754113: Blessing Christ and Saints, 10th-11th century fresco, Church of San Pietro al Monte, Civate, Italy, / Bridgeman Images

DGA910523: Votive fresco, 10th-11th century, Grotto of the Saints, Calvi Risorta, Campania, Italy / Bridgeman Images

IBE5343350: Interior of the Basilica of San Juan de Banos, Banos de Cerrato, Spain, 7th century (photo), Visigothic, (7th century) / Bridgeman Images

GRL6372167: Genoa, Museum of St Augustine: Fragment of portal jamb, by Lombard sculptor, early 11th century / Bridgeman Images

DGA2594452: Crusader fortress near sea, old city of Acre (Unesco World Heritage List, 2001), Israel / Bridgeman Images

MEP848348: Lustral basin supported by a lion, 11th - 12th Century, red Verona marble / Bridgeman Images

UDK838970: ITALY, Umbria, Spoleto, duomo / Bridgeman Images

DGA914528: Stone shelf with faces, Chateau de Lucheux (12th century), Picardy, France / Bridgeman Images

DGA914663: Strings of building (10th century), Madinat Azahara, near Cordoba, Andalusia, Spain / Bridgeman Images

DGA5186197: Clock of the Old Town Hall's tower, 1559, Rynek (Market Square), Wroclaw, Poland, 16th century, Detail, Polish School, (16th century) / Bridgeman Images

DGA644557: Fortified Church of Bjernede at Soro, 1150-1175. Denmark, 12th century. / Bridgeman Images

DGA644710: Ruins of abbey founded by Cistercian monks, 1143, Alvastra, Sweden. / Bridgeman Images

HGP2629374: Medieval gatehouse from the east, Helmsley Castle, Yorkshire (photo) / Bridgeman Images

DTO3429574: View of the medieval fortified city of Carcassonne, Southern France (photo) / Bridgeman Images

DTO3429577: View of the medieval fortified city of Carcassonne, Southern France (photo) / Bridgeman Images

DGA1131897: Maggiore fortress, medieval origin, Assisi, Umbria, Italy / Bridgeman Images

UIG1569160: Covered Bridges With Medieval Watchtowers, Strasbourg, France (photo) / Bridgeman Images

DGA1130146: Medieval walls of Montagnana, 14th century, Veneto, Italy / Bridgeman Images

JEB4845203: Gothic architecture. Genealogy of Christ - Tree of Jesse (detail): Christ with the 7 Doves. 1150. Stained glass of the Royal Portal. Cathedrale de Chartres. / Bridgeman Images

GNG5260802: Saint Michel de Cuxa abbey cloister, Cuxa, France / Bridgeman Images

MOR3707117: Entrance to the Mudéjar Chapel of San Bartolomé, a 15th-century funerary chapel, Cordoba, Spain (photo) / Bridgeman Images

MAE3469146: Puente Romano, Córdoba, Andalucía, Córdoba, Spain (photo) / Bridgeman Images

IMB4884211: Fortress of the Crusaders; medieval castle; Order of St. John; residential tower; Kolossi near Limassol; Southern Cyprus; Republic of Cyprus; Mediterranean Sea; Europe / Bridgeman Images

THA781769: Canterbury Cathedral (oil on canvas), Earp, Henry (1831-1914) / Bridgeman Images

GCL3149921: CORDOBA MOSQUE 8th century Grand Mosque in Cordova, Spain. / Bridgeman Images

PC991670: Tiled floor, c.1460, Palazzo Venezia, Rome, Italy (photo) / Bridgeman Images

TRK1031052: Spain. San Millan de la Cogolla. Monastery of San Millan de Suso. Exterior. / Bridgeman Images

TRK878770: Hagia Sophia. Tribune of Singers. Istanbul. / Bridgeman Images

DGA2583428: View of the fortified town of Carcassonne (UNESCO World Heritage List, 1997), Languedoc-Roussillon, France. / Bridgeman Images

DGA3938941: Plans of mines and underground tunnels filled with explosives (K) and resulting explosion destroying the above walls (L), copperplate engraving from Diffesa et Offesa Delle Piazze, by Pietro Paolo Floriani, published by Giuliano Carboni, Macerata, 1630 / Bridgeman Images

JB148456: Archangel Gabriel (mosaic), Russian School (11th century) / Bridgeman Images

SQ336107: Porta dei Fiori (photo) / Bridgeman Images

XPC341113: North transept (photo) / Bridgeman Images

XPC341151: South rose window (photo) / Bridgeman Images