He was back in Italy, at Rieti, in September, 1288, when he subscribed a bull for Pope Nicholas IV. Later in the year, in Rome, he was a member of an examination committee of an abbot-elect. On 28 January 1289 he is mentioned as having been an Auditor in the case involving the canonical election of a
bishop of Avignon. Two days later he was assigned the task of consecrating the newly approved Archbishop of Crete. In September 1290 Cardinal Giovanni served on the examination committee that investigated the contested election to the Bishopric of Alatri. In March 1291 he was a member of the committee that reviewed the election of the Abbot of S. Albans. At nearly the same time, he did the same in the case of the monastery of S. Pietro in Perugia. On 5 March 1291 Pope Nicholas granted Cardinal Giovanni Boccamazza the power to investigate and reform the apparently large number of encroachments and illegal occupations made by various persons upon the properties belonging to the Lateran Basilica. The Senators and other magistrates of Rome were ordered to assist the Cardinal in restoring the properties of S. Giovanni Laterano. The same service was imposed on Cardinal Giovanni with respect to the Premonstratensian monastery of S. Quirico
de valle introducti in the diocese of Reate. He was then empowered to do the same for the Monastery of Farfa. At the end of November 1295 Cardinal Giovanni was present and working in the Roman Curia, and was one of eighteen cardinals who received a distribution from the funds of the Treasury of the College of Cardinals. On 12 March 1296 he was one of twenty-one cardinals who received a 1/18 share in the payment of 2000 livres Tournois presented by the Procurators of the Abbot of Cluny. At Easter 1296 he had his share of 600 gold florins presented by the Archbishop of Florence; and likewise a share in the 400 gold florins presented by the Bishop of Tortona in Lombardy. On 29 April he shared in the 600 florins paid by the Bishop of Famagusta. At Pentecost 1296, eighteen cardinals shared in the 1900 florins presented by the Bishop of Séez; and a distribution of the 500 livres Tournois paid by the Archbishop of Rouen; and a 1/23 share in the 50 livres of the Bishop of Teramo. On 29 June 1296 there was a distribution of 500 florins paid by the Bishop of Patras. Around the Feast of S. Michael, 29 September 1296 he received a share of the payment made through the bankers of the Abbot of S. Victor of Marseille. On 10 May 1297 he was present at the degrading of Cardinals Jacobus and Petrus Colonna, from whose confiscated income Pope Boniface VIII granted a half to the cardinals, nineteen of whom are named, included Giovanni of Tusculum. He also participated in a distribution of 5 gold pieces which had been offered by the Archbishop of Strigonia at his
ad limina visit. On 24 June 1297 he was one of twenty-two cardinals who received his share of the money offered by the Abbot of S. Justinus in Padua; of the money offered by the Bishop of Padua; and of the money brought by the Proctor of the Bishop of Siena. At Easter 1298 the Archbishop of Tours visited Rome, and presented the College of Cardinals with 200 livres Tournois, which was divided among fourteen cardinals, including Giovanni of Tusculum. At the same time the sum of 2500 florins out of the payment of the Bishop of Zaragoza was distributed to the same cardinals; and a distribution from the sum of 2000 florins paid by the Bishop of Pamiers. On 20 May 1298 the 500 florins brought by the Bishop of Lodève was shared by eighteen cardinals in the Curia; at the same time there was a distribution of the 1000 gold florins paid by the Bishop of Urgel; and a distribution from the 500 livres Tournois presented by the Archbishop of Rouen. On 2 June 1298 the Abbot of Subiaco paid 300 gold florins owed by his predecessor, which was shared by twenty cardinals. On 5 September 1298 there was a distribution of the payment of 180 livres Tournois made by the Abbot of the Major Monasterium in Tours, with a 1/15 share coming to Cardinal Giovanni of Tusculum. These are only examples, showing the very large, if irregular, income of a cardinal at the time, and indicating that a cardinal was present in the Roman Curia at the time. Cardinals who were not present in the Curia (except occasionally deceased cardinals, whose estates benefitted from a late payment of dues) did not share in the distributions; this applied to Papal Legates, who had to be paid by the Pope through the Apostolic Camera, not by the Camera of the College of Cardinals. On 1 February 1301 Cardinal Giovanni of Tusculum, who had been acting as Assessor (judge) on appointment by Boniface VIII, pronounced his verdict in the case of the contested election of Leo, Bishop of Soli in Cyprus. On 20 May 1301 he and three other cardinals, Jean de Cressi, Robert de Pontigny and Matteo Rosso Orsini, were given the mandate to choose a new Abbot of the Monastery of S. Richard in the Diocese of Amiens. In June 1301 he was Auditor in the request that the Cathedral of Sagunto be transferred from regular to secular clergy. On 20 September 1301 his name heads the list of fifteen cardinals, ahead of Bishops Theoderic (Civitas Papalis) and Leonardo (Albano), subscribing to the papal grant of privileges to the Monastery of Santa Croce Saxivivo in the Diocese of Foligno. Cardinal Niccolò Boccasini, OP, Bishop of Ostia, who would normally have signed first as senior Cardinal Bishop, was serving as Legate in Hungary. When the year 1301 began, the Curia was resident at the Lateran Palace in Rome; from 1 May to mid-October it was in Anagni; from 17 October to the end of the year it was back at the Lateran. In January 1302 Cardinal Giovanni served on a committee to examine the election of the Bishop of Cammin in Germany. On 2 July 1302 he is noted as having on a committee which examined the election and person of John, Abbot of Holy Cross Monastery in Waltham in the Diocese of London. In 1302, Cardinal Giovanni Boccamazza was Canon of the Cathedral of Amiens. At the beginning of 1303 Cardinal Giovanni was consulted by the Pope concerning the depredations which had taken place against the Chapter of the Cathedral of Cambrai. ==Papal Elector==