E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
in Christian art. St. Stephen (the Pope), and Thomas Becket are represented as immolated before an altar. St. Canute is represented as lying before an altar. St. Charles Borromeo is represented as kneeling before an altar. St. Gregory (the Pope) is represented as offering sacrifice before an altar. And the attribute of Victor is an altar overthrown, in allusion to his throwing down a Roman altar in the presence of the Emperor Maximian.
Led to the altar, i.e. married. Said of a lady. The altar is the communiontable railed off from the body of the church, where marriages are solemnised. The bride is led up the aisle to the rail.