The domes of the High Middle Ages (c. 1000-1300) built by Arab Muslim and Western European Christian states were influenced by the East-West Schism, the Crusades, and the Reconquista. There are early examples of muqarnas elements supporting domes from the Fatimid Caliphate and the Abbasid Caliphate in the 11th century, as well as crossed-arch domes in the Taifas of al-Andalus. The domes of Norman Sicily blended Byzantine and Islamic elements. Christian domes under Byzantine influence used pendentives and were built over Greek-cross plans. Romanesque church domes, especially those of the Holy Roman Empire beginning around 1050, were generally octagonal on squinches and hidden externally within crossing towers.

Domes on pendentives appear in the Aquitaine region of France after the beginning of the Crusades in 1095, apparently based upon Byzantine models. Distinctive domes on pendentives were also built in Spain during the Reconquista, in addition to Christian crossed-arch domes similar to that of the earlier Great Mosque of Córdoba. A series of centrally planned churches were built by the Knights Templar throughout Europe, modeled on the Church of the Holy Sepulchre, with the Dome of the Rock at their Temple Mount headquarters also an influence.

Bulbous domes were used to cover large Islamic buildings in Syria after the eleventh century, following an architectural revival there, and the present shape of the Dome of the Rock's dome likely dates from this time. Islamic domes of the Ayyubid dynasty tended to be smooth and replaced the curved squinch forms of the Fatimids with more angular forms. Madrassas often included a domed mosque or mausoleum. The Mamluks built tombs with a variety of dome forms and developed transition zones that used corbelled layers of muqarnas and stalactite elements.

Holy Roman Empire

In Italy, the frequency, quality, and scope of dome construction increased beginning in the 11th century (although not in the city of Rome) and they were used in baptisteries, princely chapels, cathedrals, bell towers, and pieve churches. Early examples include the (c. 1005), the baptistery of the Basilica di San Vincenzo in Galliano (1007), the (c. 1040), and the (1040). The Biella baptistery included a turret over the dome that was unconnected to the space below.

The 4th century structure at St. Gereon in Cologne influenced the Ottonian building at Deutz Abbey (1002-1019).

Copies of the Palatine Chapel at Aachen include an (c. 1020), (reconstructed in the 11th century), and the Westbau of Essen Minster (c. 1039-1058). The chapel of Saint Andrew in the (c. 1020), may have been a copy of the Aachen chapel, but only in diameter. It was destroyed in 1777.

Kingdom of France

The rotunda of the Abbey of St. Bénigne in Dijon was built around the 11th century. Because of its dedication to "the Virgin and 'all the saints'" and its dome's central oculus, it is thought to be inspired by the Pantheon in Rome, which had been rededicated in 613 as the Church of Sancta Maria ad Martyres.

Catalan counties

In Catalonia, there appears to have been a "dramatic increase in the quantity and quality of building in the first half of the eleventh century" and the construction of domes on squinches, rather than the pendentives on comparable buildings, may indicate the use of masons with experience building domes in Al-Andalus.

County of Barcelona

The so-called first Romanesque style of churches in the early 11th century included examples in Spain with domes on squinches. The domes tend to be dark and sometimes included small windows at the base. The church of Santa Maria de Ripoll was consecrated in 1032, but was rebuilt after a fire in 1835.

The church of Church of Sant Vicenç in the Castle of Cardona has a dome on squinches. The Church of Sant Vicenç was built by 1040 and there is another example at Corbera. The Corbera church may not have been intended to have a dome when the foundations were laid and the crossing bay was narrowed to create a square by the insertion of additional arches on the north and south sides. The dome was covered by a square belfry on the exterior.

The small church of San Pablo in Barcelona has a central dome and triapsal arrangement resembling the churches of eastern Christianity.

County of Empúries

The church of Sant Miquel in Cruïlles was consecrated in 1035 and has a dome at its crossing covered on the exterior by a drum and short square tower.

Taifas of Al-Andalus

Taifa of Toledo

The nine bays of the Mosque of Cristo de la Luz, built about 50 years after the crossed-arch domes of the Great Mosque of Córdoba, contain a virtual catalog of crossed-arch dome variations.

The building now known as the Capilla de Belen in Santa Fe de Toledo has a crossed-arch dome that may date to the 11th century under the Banu Du-l-Nun sovereigns of Toledo. It has also been proposed as dating from the 13th or 14th centuries.

Taifa of Zaragoza

No other crossed-arch examples survive in Spain until the dome of the mosque of the Aljafería Palace, built for Ibn Jafar Al-Muqtadir, who reigned from 1049 to 1081.

Republic of Ancona

The dome of the may have been built between 1034 and 1050.

Fatimid Caliphate

The local brick dome technique of Eqypt in the 11th century used a transitional zone with trefoil or pointed arch squinches.

There are 11 examples of domes with early brick muqarnas elements in their transition zones between 1050 and 1150, including (c. 1050), Bāb Zuwayla (1092), the Tomb of Shaykh Yūnus (1094), the Coptic chapel of Abū al-Sayfayn (1094-1121), the Tomb of Sayyida ʿĀtika (1120-1125), the Tomb of Muḥammad al-Jaʿfarī (1120-1125), a tomb at Qūṣ (1120-1130), a tomb across from the Khānqāh Sulṭān Baybars al-Jāshnakīr (c. 1133), the Mashhad of Sayyida Ruqayya (1133), and the Mashhad Yaḥyā al-Shabīh (c. 1150). The domes are around 3 meters wide, but the largest diameter is the 7.58 meter dome of the Mashhad Yahyā al-Shabīh.

The tomb at Qūṣ used small trefoil arches in the upper level of the transition zone to create a sixteen-sided base for the dome.

Most of the domes have two layers of brick muqarnas forming a diagonal trefoil arch over the corners of a square bay, likely a development of the squinch arch, and this would continue until the 12th century. The walls between the arches mirrored the trefoil pattern, but with a single window until 1130. Then the single window transitioned to a three-window arrangement with one window over two others, as seen in the Mashhad of Sayyida Ruqayya and the Mashhad Yaḥyā al-Shabīh.

East–West Schism

The schism between the churches of Constantinople and Rome was reflected in architecture. The Greek cross and domes of Byzantine architecture were found in areas of Byzantine cultural influence. An example is the domed Greek cross church in Genga, an area of indirect eastern influence. At the in Barzanò, a third phase of construction added a hemispherical dome on squinches over the existing central bay of the building, possibly in the late 11th century.

Octagonal cloister vaults appear "in connection with basilicas almost throughout Europe" between 1050 and 1100. The precise form differs from region to region. They were popular in medieval Italy, in brick. Romanesque domes were typically octagonal in plan and used corner squinches to translate a square bay into a suitable octagonal base. The domes at the intersection of a church's nave and transept were generally found within crossing towers, which concealed the domes externally. Called a tiburio, this tower-like structure often had a blind arcade near the roof. Romanesque basilicas with crossing domes were widespread in Italy. They were built across southern Europe in the 11th and 12th centuries and hundreds of examples under church crossing towers exist in Spain and southern France.

The use of domes declined in Western Europe with the rise of Gothic architecture. Gothic domes were uncommon due to the use of rib vaults over naves, and with church crossings usually focused instead by tall steeples, but there are examples of small octagonal crossing domes in cathedrals as the style developed from the Romanesque. The domes of Romanesque and Early Gothic Latin-cross churches rarely span more than the width of the nave. Spaces of circular or octagonal plan were sometimes covered with vaults of a "double chevet" style, similar to the chevet apse vaulting in Gothic cathedrals.

Holy Roman Empire

The Chapel of our Lady at the Imperial Palace of Goslar (begun around 1060) has since been destroyed, but had two concentric octagonal walls and was said to have been modeled on the Aachen church.

The architecture of the areas of northern Italy that were a part of the Holy Roman Empire developed differently from the rest of the Italian peninsula. The earliest use of the octagonal cloister vault within an external housing at the crossing of a cruciform church may be at Acqui Cathedral in Acqui Terme, Italy, which was completed in 1067. This became increasingly popular as a Romanesque feature over the course of the next fifty years. The first Lombard church to have a lantern tower, concealing an octagonal cloister vault, was San Nazaro in Milan, just after 1075. Many other churches followed suit in the late 11th and early 12th centuries, such as the Basilica of San Michele Maggiore in Pavia (the coronation church of the Kingdom of Italy within the Holy Roman Empire) and the Basilica of Sant'Ambrogio in Milan. The Monastery of Capo di Ponte has a crossing dome that dates from about 1090. At Sant'Ambrogio, the original plan for the church did not include a domed crossing and it was modified to include one, as also happened at Pisa Cathedral (funding for which was provided by Emperor Henry IV in 1089 and Emperor Henry V in 1116) and Speyer Cathedral (the burial church of the Salian dynasty of Holy Roman Emperors). The crossing domes at Pavia, Pisa, and Speyer were all completed around 1080 but the exact order of precedence is unresolved.

The renovation of Speyer Cathedral, the largest of the Imperial Cathedrals of the Holy Roman Empire, was begun around 1080 by the Emperor Henry IV, soon after he had returned from a trip to Canossa in northern Italy. Although the church had only just been consecrated in 1061, Henry called upon craftsmen from across the empire for its renovation. The redesign included two octagonal cloister vaults within crossing towers, one at the east crossing with an external dwarf gallery and one at the west end. This was very soon imitated elsewhere and became the model for later Rhenish octagonal domes, such as those of Worms Cathedral (c. 1120–1181) and Mainz Cathedral (c. 1081–1239). Many German Imperial cathedrals feature domes at their crossings.

The domes of Pisa Cathedral and Florence Baptistery may be two of the earliest domes in Tuscany and were the two largest until about 1150. The smaller dome of the may have been built in the early 12th century.