MENTION of my discovery of the Carlbury milepost, near Piercebridge, on the blog prompts Tim Brown in Ferryhill to take us further afield, to Corbridge.

There stands a very impressive Roman milestone, which is believed to have been erected in the reign of Emperor Constantine (306AD-337AD). It shows that Corbridge is CXL (140) miles from York, and that the stone itself was put there by the 20th Legion whose emblem was a rather happy-looking boar trotting along.

The late Victorian cast iron Carlbury milepost is a very humble affair in comparison, yet it once had a Roman neighbour.

The Carlbury miley is on the A67 Darlington to Barnard Castle road, and in 1953 in a gravel quarry to the north of the road near Piercebridge another Roman milestone was found.

Piercebridge is, of course, the site of a Roman crossing of the Tees, and the milestone was found more than 500 yards to the west of the Roman road of Dere Street.

The stone is now in Bowes Museum in Barnard Castle. Whether it was once part of the furniture of Dere Street or whether it came from a by-road is unknown. A couple of similar stones - fashioned rather phallicly from a buff sandstone that was probably quarried near the Roman fort at Binchester near Bishop Auckland - were once found beside the A66 as it crossed over Stainmore.

The weatherworn Piercebridge stone has the remains of a crude inscription at its top: "MPCGallVall Maximiano el".

This fragment of Latin apparently translates as: "For the Emperor Caesar Galerius Valerius Maximianus Pius Felix".

Galerius was born a Bulgarian peasant herdsman in about 250AD. But he did well in the Roman army and, by 293AD, he was appointed a junior emperor of Turkey, fighting against Goths and Persians.

In 305AD he rose to rule the whole of the Roman Empire - but his was not a happy reign.

There was rebellion in Rome, which forced him into a semiretirement back in Bulgaria where he contracted a horrible disease: his genitals swelled up, worms infested his ulcerous body and stank so badly that some of his doctors were unable to approach him.

He executed them.

When his other doctors failed to save him, he executed them too.

Galerius died in May 311AD, repenting on his deathbed for persecuting Christians.

We can, therefore, say that the Roman milestone of Piercebridge dates from 305AD to 311AD and so is probably a year or two earlier than the one Tim discovered in Corbridge.