To understand the architectural sculpture of medieval religious buildings as fuUy as possible it must be set within its architectural, social and religious contexts. I argue that medieval religious buildings, as institutionalized points of contact with the sacred, were perceived as Hmtnal spaces -where the everyday world overlapped with the supernatural realms of saints, angels and demons. Embedded into the fabric of the church and thereby identified with it, and rarely following any particular patterns of placement, architectural sculpture presented a visual evocation of Hminahty through its use of some of the key techniques of grotesque art, for example, hybridity, distortion, exaggeration, and replication. These images drew attention to the space articulated by the building as similarly ambiguous and unclassifiable, ideas well-suited to its role as God's house on earth. Lirninal locations are, however, dangerous as well as potent and merit some form of protection from the potentially malefic energy of the sacred. Medieval architectural sculpture therefore has an apotropaic purpose as well; identification of Hminal space and protection from it are perhaps its two most fundamental aspects. Imagery considered effective apotropaia is also highly esteemed, which may reflect its prolific use on high status buildings. Thus, "grotesque" images, rather than an aberrant feature of medieval religious art, are instead entirely appropriate. Close analysis of various aspects of the imagery reveals a resistance to definitive interpretation and permeability of meanings, substantiating the idea that these were intentionally liminal images. Contents a%% v4#bMwA^^m%%b joaa Roofline Images 97 Romanesque Corbel-tables 98 Cornices, Friezes, Gargoyles and Grotesques 103 Arches 107 Voussoirs 107 Lintels and Tympana 108 Capitals 110 Apexes 111 Terminations 112 Reveals 112 Misericords and Roof Bosses 112 Apotropaic Heads and Other Images 114 Antefixa and Romano-British Heads 118