In June 1549, Aldrovandi was accused and arrested for heresy on account of his espousing of the anti-trinitarian beliefs of the Anabaptist Camillo Renato. By September, he publicly abjured, but was nevertheless transferred to Rome, and remained in custody or house arrest until absolved in April, 1550. During this time, he befriended many local scholars. While in light captivity there, he became more and more interested in botany, zoology, and geology (he is credited for the invention/first written record of this word). From 1551 onward, he organized a variety of expeditions to the Italian mountains, countryside, islands, and coasts to collect and catalogue plants.