In 1604 he obtained leave to travel and spent the next four years in Europe, mainly with Swiss and German Calvinists, spending a winter at the University of Heidelberg with David Pareas and Abraham Scultetus.

[5] Of strongly anti-Catholic and pro-Calvinist religious views, Hakewill was one of the two clergymen appointed in 1612 to preserve Prince Charles "from the inroads of popery."

His decision however in 1622 to present the prince with a treatise written by himself and arguing against the ongoing negotiations for a Spanish match led to the abrupt end of his career at court.

The treatise was shown to the prince's father, James I of England, who committed Hakewill to a prison for a brief period and appointed Lancelot Andrewes to rebut the tract.

Hakewill's will shows that, despite his theological leanings towards radical Protestantism, he remained politically a royalist[12] and loyal to the Church of England as established.