How drunk you were was always up to the enforcing officer until tests were introduced in the 20th Century.

I can only attest for English law. Although other countries may have previously have had laws concerning drink driving in past centuries, the texts of those laws are not readily available on the internet. I'm fairly sure that driving under the influence was first reported and punished during the times of the Roman Empire or much earlier.

The Offences Against the Person Act 1861 provided for punishment for "Drivers of carriages injuring persons by furious driving". The Act covered "wilful misconduct and wilful neglect [..] which may do or cause bodily harm to any person whatsoever." Although not clear in its language, wilful misconduct and wilful neglect could be interpreted as being drunk in charge of a vehicle.

Further clarification was enacted with the Licensing Act 1872, which, along establishing penalties for people found in a drunken state in public, stated that "Every person who is drunk while in charge on any highway or other public place of any carriage, horse, cattle, or steam engine, or who is drunk when in possession of any loaded firearms, shall be liable to a penalty not exceeding forty shillings, or in the discretion of the court to imprisonment for any term not exceeding one month."

It is noteworthy that Westminster took less than ten years to react to the advent of the self propelling steam engine.