Which preposition to use with boyne

in Occurrences 2%

We gain a like view of the civil state in the record of a great assembly convened in 1167 by the energetic and enterprising Connacht king: "A great meeting was called together by Ruaidri Ua Concobar and the chiefs of Leat Cuin, both lay and ecclesiastic, and the chiefs of At-boy,the Yellow Ford across one of the streams of the Boyne in Meath.

to Occurrences 1%

Concobar, therefore, marched toward the Headland of the Kings, across the Boyne to the southward, and facing the northern bank where are the pyramids of the Dagda Mor and the De Danaans.

Which preposition to use with  boyne