Yeomen Warders
The Yeomen Warders provided the permanent garrison of the Tower, but the Constable of the Tower could call upon the men of the Tower Hamlets to supplement them when necessary. The Tower Hamlets, aka Tower Division was an area, significantly larger than the modern London Borough of the same name, which owed military service to the Constable in his "ex officio" role as Lord Lieutenant of the Tower Hamlets.