[2] Fifty-four cardinals participated in the conclave which took place from 19 July to 6 August,[3] following the death of Gregory XV.

Ludovisi attempted to increase his influence over the conclave by becoming allies with the cardinals who originated from regions controlled by the Habsburgs.

It was anticipated that Campori's age of 66 would be a benefit, because a Spanish memorandum had revealed that they viewed older cardinals as less likely to develop an independent foreign policy as pope.

[1] The first scrutiny of the conclave was significant because it revealed that Gregory XV's reform intended to discourage cardinals from voting for their friends in the first round had not been successful.

These rumours caused other cardinals to lose good will towards Borghese, coupled with the alleged fact that the summer heat had begun to exhaust them.

[5] During Paul V's papacy Urban was noted in a series of biographies on potential cardinal electors for being a writer and poet.