take the shilling

verb3

1. •
   (UK, historical) To enlist as a soldier in the British army or navy by accepting a shilling from a recruiting officer.

   • [O]ne fellow was jilted by his mistress and took the shilling in despair; […] — 1852
2. •
   (old-fashioned) To enlist as a soldier of any military force; to join the armed forces.
3. •
   To be on the payroll of an organization; to work for an organization.