What is Ancient Writings?

Legal Definition
Evidence. Deeds, wills, and other writings more than thirty years old, are considered ancient writings. They may in general be read in evidence, without any other proof of their execution than that they have been in the possession of those claiming rights under them. Tr. per Pais, 370; 7 East, R. 279; 4 Esp. R. 1; 9 Ves. Jr. 5; 3 John. R. 292; 1 Esp. R. 275; 5 T. R. 259; 2 T. R. 466; 2 Day's R. 280. But in the case of deeds, possession must have accompanied them. Plowd. 6, 7. See Blath. Pres. 271, n. (2.)
-- Bouviers Law Dictionary
Legal Definition
Wills, deeds, or other documents upwards of thirty years old These are presumed to be genuine without express proof, when coming from the proper custody.
-- Black's Law Dictionary
Legal Definition
Documents over thirty years old.
-- Ballentine's Law Dictionary