[...Embery : is a variant of the surname Amery which is an English Patronymic name. The name was brought to the British Isles with the Normans, many of whom were referenced by the towns they emigrated from, or by the Norman given names of their fathers. Amery is derived from Old French amal =bravery + ric =power, and derivatives include Amory, Emery, Emary, Emberry, Embrey , and Imbrey , among others....]
Embury is just another variant of Embery and the rest.
Though i have to say:
(from www.behindthename.com: AMALRIC Gender: Masculine Usage: Ancient Germanic Pronounced: A-mal-rik, a-MAL-rik [key] Extra Info: Related Names Options: Contribute Information Derived from the Germanic elements amal "work, labour" and ric "power". This was the name of two rulers of the Latin Kingdom of Jerusalem in the 12th century.)
Those are Germanic elements and not Old French (important difference).
The same site, www.behindthename.com also backs up the meaning of Emery. Search for 'Emory', then click on 'Emery' and then on 'Emeric'. There it says: 'work rule', which is the same basically as Amalric.
But http://www.last-names.net/surname.asp?surname=Britton;Britten;Brittan says: A native of Britain, the ancient name of England. Several derivations have been given to Britain, such as Brydon or Prydyn, Welsh, the fair tribe, or brave men . Bridaoine, Gaelic, from Bri, dignity, and daoine, men. Pryddain, the fair and beautiful isle. Brait or Briand, extensive, and in, land. Brit-tane, the land of tin.
I tend to believe the latter source because of its reputation, and Prydyn is indeed the Welsh name for an area where the Picts live (as i understood, anyone know for sure?) and in that case the meaning of the first website doesn't make any sense. To add to that, a person that makes bridles is called in English a lorimer according to the following site: http://www.newyorkancestry.com/factsfun3.htm