The London Borough of Croydon came into being on 1 April 1965. It was formed largely from the territory of the former County Borough of Croydon, and the Urban District of Coulsdon and Purley. The coat of arms and badge were granted on 10 December 1965. In the pictorial language of heraldry, the coat of arms of the London Borough of Croydon recalls earliest recorded 'local government' of Croydon.
Domesday Book says that, in 1086, "Archbishop Lanfranc holds a demesne in CROINDENE." "The Abbey of St Peter of Chertsey holds Watendone" and "The Abbey itself holds Colesdone" The Abbey of St Peter of Winchester holds Sandestede."
The Arms commemorate the three lords of the ancient manors of Croydon, Coulsdon and Sanderstead. Canterbury is represented by the flowering cross of John Whitgift and by the two crosses from The Arms of the See of Canterbury which hang from the collars of the lion and horse which support the shield. Chertsey Abbey contributes the crossed swords and keys to the head of the shield.
The black lion is from The Arms of Hyde Abbey (the later name of the Abbey of St. Peter of Winchester) to represent the Manor of Sanderstead. The shield's second supporter is from The Arms of the Earls of Surrey, the ancient feudal lords of the County of Surrey.
The coat of arms also includes references to the more recent history of the London Borough of Croydon. Thus the oak and beech trees from the arms of the Urban District of Coulsdon and Purley contributed their branches to the crest, where they appear on either side of the fountain which is taken from The Arms of the County Borough. The fountain is the blue and white disc which, in the heraldic convention, represents water, and the mural or walled crown on which it stands is the sign of municipality. The supporting lion for Sanderstead stood rampant on the Coulsdon and Purley shield, and the keys of St. Peter of Chertsey, which were held aloft on the Urban District crest, reappear on the London Borough shield.
The Motto is - Ad Summa Nitamur - Let us strive after Perfection.
The Shield is white (or silver), bearing a black cross with its arms terminating in fleur-de-lys shapes, and surmounted by five gold discs. (These elements are all taken from the personal arms of Archbishop John Whitgift.) At the top of the shield are a red and blue pair of crossed swords, and a red and blue pair of crossed keys. (A sword is the emblem of St Paul; and two keys are the emblem of St Peter: these elements are taken from The Arms of Chertsey Abbey, which owned the manor of Coulsdon in the middle ages).
The Crest (on top of the helmet) consists of a 'walled' crown (symbolising a town), surmounted by a disc of wavy blue and white stripes (symbolising water, and taken from the County Borough arms), which is flanked by an oak branch and a beech branch (taken from elements in the Coulsdon and Purley arms). The Mantling (the decorative cloth, flowing from behind the helmet) is black and white.
The Supporters (the animals holding up the shield) are a black lion (taken from The Arms of Hyde Abbey at Winchester, which owned the manor of Sanderstead in the middle ages), and a white horse (taken from The Arms of the Earls of Surrey, but also, perhaps, representing the manor of Whitehorse in Croydon). They both wear collars (white and black respectively), from which hang spike-footed crosses (taken from The Arms of the See of Canterbury).