Is an architectural style of Medieval Europe characterized by semi-circular arches. There is no consensus for the beginning date of the Romanesque architecture, with proposals ranging from the 6th to the X century. It developed in the XII century into the Gothic style, characterised by pointed arches. Examples of Romanesque architecture can be found across the continent, making it the first pan-European architectural style since Imperial Roman Architecture. The Romanesque style in England is traditionally referred to as Norman architecture.

Combining features of Roman and Byzantine buildings and other local traditions, Romanesque architecture is known by its massive quality, thick walls, round arches, sturdy piers, groin vaults, large towers and decorative arcading. Romanesque architecture was the first distinctive style to spread across Europe since the Roman Empire. With the decline of Rome, Roman building methods survived to an extent in Western Europe, where the successive Merovingian, Carolingian and Ottonian architects continued to build large stone buildings such as monastery churches and palaces. In the more northern countries Roman building styles and techniques had never been adopted except for official buildings, while in Scandinavia they were unknown. Although the round arch continued to be utilised, the engineering skills required to vault large spaces and build large domes were lost. There was a loss of stylistic continuity, particularly apparent in the decline of the formal vocabulary of the Classical Orders. In Rome several great Constantinian basilicas continued in use as an inspiration to later builders. Some traditions of Roman architecture also survived in Byzantine architecture with the 6th-century octagonal Byzantine Basilica of San Vitale in Ravenna being the inspiration for the greatest building of the Dark Ages in Europe, the Emperor Charlemagne's Palatine Chapel, Aachen, Germany, built around the year AD 800.

Dating shortly after the Palatine Chapel is a remarkable 9th-century Swiss manuscript known as the Plan of Saint Gall and showing a very detailed plan of a monastic complex, with all its various monastic buildings and their functions labelled. The largest building is the church, the plan of which is distinctly Germanic, having an apse at both ends, an arrangement not generally seen elsewhere. Another feature of the church is its regular proportion, the square plan of the crossing tower providing a module for the rest of the plan. These features can both be seen at the Proto-Romanesque St. Michael's Church, Hildesheim, 1001—1030 Architecture of a Romanesque style also developed simultaneously in the north of Italy, parts of France and in the Iberian Peninsula in the 10th century and prior to the later influence of the Abbey of Cluny. The style, sometimes called "First Romanesque" or "Lombard Romanesque", is characterised by thick walls, lack of sculpture and the presence of rhythmic ornamental arches known as a Lombard band.

Romanesque elements are present in The National Romantic style of Art Nouveau (Nordic architectural style in St. Petersburg) and Russian Revival style. Unlike much nostalgic Gothic Revival style architecture elsewhere, National Romantic architecture expressed progressive social and political ideals, through reformed domestic architecture.