What are hiddes?

Some articles on hiddes:

Tjerk Hiddes De Vries - After His Death
... Tjerk Hiddes is buried in the Grote Kerk of Harlingen his grave memorial has been destroyed ... Four days after his death his son Tjerk Hiddes the Younger was born, who shortly after his birth was promised a future captain's commission by the admiralty to honour the memory of his father ... Hiddes de Vries was succeeded as Lieutenant-Admiral of Frisia on 16 March 1667 by Baron Hans Willem van Aylva ...
Admiralty Of Friesland - History - Second Anglo-Dutch War
... He was succeeded as Lieutenant-Admiral of the Frisian fleet by Tjerk Hiddes ... Tjerk Hiddes distinguished himself by his bravery ... Tjerk Hiddes was mortally wounded, Rudolf Coenders killed ...