The saint honored here is Walhère van Onhaye (about 25 km west of here).
He was born in the early 12th century in Bouvignes-sur-Meuse, where his birthplace is still located.
According to a document from 1190, he was appointed dean of Florennes. It was a troubled time, in which serious conflicts took place between the various abbeys, with the Count of Namur and the Prince-Bishop of Liège often having to intervene. Apparently Walhère tried to intervene to calm the parties, and to this end went to Hastière. While returning by boat across the Meuse, he was allegedly murdered and thrown into the river. The next day his lifeless body was found by some women walking along the shore. This happened in 1199, probably on the 23rd of June.
The body was loaded onto a wagon that headed for Waulsort. However, the horses refused to go in that direction and instead went to Onhaye, where they stopped in front of the St. Martin's Church there. A chapel was founded in Onhaye in which there are still relics of Walhère, which were and are still venerated by the faithful.
Every year, on the first Sunday after St. John's Day (June 24), a large procession takes place that attracts many participants, even from far outside the village.
Since Walhère was killed by a blow to the head, he is invoked against headaches, and also to protect the cattle.
Source: wikipedia