 Whether commissioned officer , mercenary , or both , Standish apparently came to Holland around 1603 and , according to historian Tudor Jenks , may have seen service during the siege of Sluis in 1604 , in which Vere 's English troops were involved . The subsequent Twelve Years ' Truce ( 1609 – 1621 ) between Spain and the Dutch Republic might have ended Standish 's service . 
