The Gentleman, Knight, Baron, and the like, do wear their helments with the beaver looking over the shoulder, to signify, that they, marching before their Duke or Captain (as at the first that dignity was but an office) do regard and look towards him to attend his pleasure and direction in what he will command.

– From The Blazon of Gentrie by Sir John Ferne (1586), p139


All [princes] do ensign their Chapeau and helm with a Crown of flowers and crosses. And they are enabled by observation of Armory, to wear the like helm and Chapeau,
that the Duke or King doth wear.

– From The Blazon of Gentrie by Sir John Ferne (1586), p138

Military objects used as heraldic charges

 From Inquiries into the Origin and Process of the Science of Heraldry in England by James Dallaway, p454

Left to right (click on the names for more examples of each charge):

The escarbuncle. While its origin is not certain, it is believed to have been a way of reinforcing wooden shields. It is probably best known as the badge of Henry II of England, taken from the ancient arms of the French region of Anjou.

The helmet, while most often seen as a component of complete achievements, does occasionally appear by itself as a charge.

The pheon was an ancient dart head. Although its shape and function are similar to the arrowhead, the pheon is barbed.

Arms of Michael I Apafi

Prince of Transylvania 1662-1690 (1632-1690)

Blazon: Per pale I per fess argent and azure, a demi-eagle displayed issuant from the partition line sable, armed or, langued gules, II or seven towers gules 3, 3, and 1; on a chief azure in dexter a sun or and in sinister a crescent increscent argent; overall in the fess point an escutcheon azure a vine palewise proper surmounted by a sword bendwise sinister argent, hilted or, overall a helmet of the second within a bordure of the third (Apafi)