Death under Shield
Death in battle.
“Her imagination had been familiarised with wild and bloody events ... and had been trained up to consider an honourable `death under shield' (as that in a field of battle was termed) a desirable termination to the life of a warrior.” —Sir W. Scott:The Betrothed, chap. 6.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894