Coat of arms of Louis Mountbatten, 1st Earl Mountbatten of BurmaArms of the Earl Mountbatten of BurmaShield – Quarterly: first and fourth, azure, a lion rampant double queued barry of ten argent and gules, armed and langued of the last, crowned or, within a bordure compony of the second and third; second and third, argent, two pallets sable charged on the honour point with an escutcheon of the arms of the late Princess Alice (namely, the Royal Arms differenced with a label of three points argent, the centre point charged with a rose gules barbed vert, and each of the other points with an ermine spot sable).Crests – First, out of a coronet or, two horns barry of ten, argent and gules, issuing from each three linden leaves vert, and from the outer side of each horn four branches barwise, having three like leaves pendant therefrom of the last (Hesse); second, out of a coronet or, a plume of four ostrich feathers alternately argent and sable (Battenberg).Supporters – On either side a lion double queued and crowned all or. Motto – In Honour Bound
Note on Background

The label used by Lord Mountbatten's maternal grandmother, Princess Alice (Queen Victoria's second daughter) and which appears on Lord Mountbatten's own arms.
[1]
Heralder and NoahHK