When were dogs first kept as pets in Britain?
This is not an easy question to answer - almost certainly, dogs were living around settlements thousands of years ago, but not in the sense of being pets as they are today. This particular trend almost certainly began as a result of the Roman invasion.

Archaeological evidence has revealed how what today would be classed as toy dogs were being kept as pets at various Roman homes in the British Isles during the era of occupation. Their sudden appearance and associations in the archaeological record suggest that such dogs were actually brought from Rome by their owners, rather than being native to these islands.

There was definitely a considerable movement of dogs occurring at this early stage in history, not just in the Mediterranean but also from Britain to Rome and elsewhere in the Empire. A special official, known as the Procurator cynegii was based in the English city of Winchester with the main task of arranging shipments of dogs back to Rome where they used for fighting purposes in the amphitheatres, being pitched against other animals and even gladiators.

Julius Caesar himself remarked on the bravery and loyalty of British dogs. The largest individuals were of mastiff-type, and frequently used in battle. Their strength was such that they could reputedly break the neck of a bull with a single blow.

Unfortunately, archaeological evidence is incomplete, but based on a study of over 1000 skeletons, it is clear that dogs in Roman Britain stood between 23cm (9in) and at least 71cm (28in) in height. The biggest individuals were therefore probably similar to the giant breeds of today in terms of their size, but were far more fearsome by all accounts.