Tresayle

If the abatement happened on the death of one's grandfather or grandmother, then an assise of mort d'ancestor no longer lies, but a writ of ayle or de avo: if on the death of the great-grandfather or great-grandmother, then a writ of be sayle, or de proavo: but if it mounts one degree higher, to the tresayle, or grandfather's grandfather, of if the abatement happened upon the death of any collateral relation, other than those before-mentioned, the write is called a writ of cosinage, or de consanguineo.

If any one wishes to speak of a great-great-grandfather (tresayle) through some side line, as his grandmother’s mother’s father, he has to use an explanatory mode like the above.

Thomas Boston Clarkson, whose genealogy is given in the third pamphlet, was born in Charleston, S. C., Sept. 4, 1809. His maternal grandmother was Christiana, daughter of Thomas Boston, V.D.M., whose ancestry is traced back five generations to her tresayle, Andrew Boston, born in Ayre, Scotland, about 1597.

[…]in 1834, he prefixes to his diary a record of his ancestors, running back four generations to his tresayle, or great-great-grandfather, Joseph Towne, living in Topsfield, 1684.

In April 1600 Delahay protested to Sir Robert that on a Sunday in March 'I was assaulted and violently pulled […] , and where men see Richard Cecil your tresayle [actually his great-grand brother] use'-by the procurement of John Arnold.

However, two individuals a and b whose most recent common ancestor c is the quatrayle of the former and the tresayle (great-great-grandfather) of the latter may belong to the same lineage, because the genealogical chain connecting them consists of nine degrees of kinship.