Archaeologists said yesterday that they had uncovered the skull of Sir Richard Steele, the Irish-born essayist and dramatist, who with Joseph Addison founded the Tatler and the Spectator periodicals in the early 18th century.

The skull was discovered in a lead box in St Peter's Church, Carmarthen, west Wales.

The archaeologists had been brought in to level a tiled floor that was subsiding, and have already announced having come across the graves of George III's granddaughter and her niece at the church.

A parish guide showed that the essayist's skull was previously found in 1876 and reburied in the church crypt, but it did not detail the skull's location. The archaeologists have now found a casket that has inscribed on it the name Sir Richard Steele; he is recorded as having died in Carmarthen in 1729.

Project manager Pete Crane said: "We had doubts at first as to whether he was really there but now we have seen the casket we're sure."

The vicar, Canon Randolph Thomas, said: "This is an amazing find."