The present essay is mainly concerned with the coronation entries staged for James I and Charles II by the City of London in 1604 and 1661, and especially with the temporary arches made out of wood and canvas and erected to mark nodal points along the routes. These events have been the subjects of scholarship keenly attuned to their place in accessions more than usually demanding upon representations of the king’s majesty, in as much as James was the first Stuart king of England and, by the terms of hereditary monarchy, his grandson’s reign began twelve years before his coronation, at the moment Charles I’s head was severed from the neck. Here, however, the arches will explain, or emblematize, a particular way of conceiving architecture: as an assemblage of readily-dismountable parts like Lego bricks, or like a trophy, the ornamental group of symbolic or typical objects arranged for display. In this kind of architecture ‘classical’ ornament comprises, not the material realization of a stable, rational, and universal intellectual system elsewhere promoted by the early Stuarts’ patronage of Inigo Jones, for example, but what Sir Balthazar Gerbier in 1648 called a ‘true History’ of destruction and triumph, the result of more or less random despoliation and reassembly. What follows is not, therefore, directly concerned with majesty, nor with the arches’ iconography or their audiences, their place in London’s ceremonial geography, nor even their elaboration of the ‘complex relationships between two distinct but interconnected political domains’, the City that built them and the monarchy that graced them.