Proof seems to be missing of participation from Holland in de Crusades. This appears to be false.
Until about 1300 the former county Holland was still calles 'Frisia'. The name Holland dates back to 1101, and even then it was a limited area only. The counts of Holland were called the counts of West Friesland. About Frisians who participated in the Crusades, sufficient information is to be found in the sources.