Was it a warship or a passenger ship?

Matthew Seligmann, Brunel University London, revisits the fine lines that were drawn between commercial vessel and war ship by both sides in WWI

When the United Kingdom went to war in August, 1914, the British Admiralty immediately notified the Cunard shipping company of its intention to requisition the fast luxury liners, Lusitania and Mauretania.

This was no spur-of-the-moment decision, but reflected policy of a decade previously. In 1903, under the terms of the so-called Cunard agreement, the British government had lent funds at preferential rates to Cunard and had paid them a large annual subsidy, so they would build and run two transatlantic liners to Admiralty requirements. The ships had to be capable of a speed in excess of 24 knots.