A letter from Mathilde

Translated letter:

We, Mathilde countess of Holland make known to those in the present as well as the future who will see the presents that our beloved son, lord William of bright memory formerly/late illustrious king of the Romans, conferred on us the pasturing of the whole mound [agger] lying between the home of Floris and the home of lady Douwe, and transferred it into our hands, which we gave under the stated terms to the church of St. Mary of the Island [the Island of St. Mary], of the Premonstratensian order, in the diocese of Maastricht, for the remedy of the soul of lord Floris, our beloved husband taken from our midst to be possessed in perpetuity.

In witness of which thing and act, we have had the present charter, strength, and protection  inscribed and fortified by our seal.

Dated in Gravenzande in the year of the Lord 1261, on the Sunday between the octave of the 11,000 Virgins. 

Original letter:

Nos Maghtildis comitissa Hollandie notum facimus tam presentibus quam futuris presentia visuris quod dilectus filius noster, clare memorie dominus Wilhelmus quondam Romanorum rex illustris pasturam totius aggeris iacentis inter domum Florentii et domum domne Douwe nobis contulit et in manus nostras resignavit, quam sub prefatis terminis ecclesie de Insula beate Marie, ordinis Premonstratensis, dyocesis Traiectensis, pro remedio anime domini Florentii, dilecti mariti nostri de medio sublati libere donavimus in perpetuum possidendam.

In cuius rei et facti nostri testimonium, robur et munimen presentem cartulam fecimus conscribi et sigillo nostro communiri.

Datum in Grauenezande anno Domini M CC LXI, dominica infra octavis XIm Virginum. 

Historical context:

The countess records the gift of land which her son had given her to a church for the soul of her late husband.

Printed source:

Oorkondenboek van Holland en Zeeland tot 1299, ed. A.C.F.Koch,  3.276, #1268.

Date: