As archbishop, Terès founded the monastery of Saint Dominic in Ciutadilla, in 1588.
He collaborated in the improvements of the monastery of Saint Mary of Bovera in Guimerà, and in the hermitage of Saint Magí of Brufaganya, near Santa Coloma de Queralt.

In 1589, he got for Tarragona the publication of the privilege of Studium Generale, granted by Philip II of Spain.
This was celebrated with rejoicing and public festivities all around the city.

In 1591, Terès granted privileges of baptismal fonts to la Riba, due to the difficulty that represented for the villagers to go to Vilaverd.

In 1592, Terès ordered to build, in the cathedral of Tarragona, the chapels of Saint John the Evangelist and Saint Fructuosus, to the Renaissance architect Pere Blai.

In 13 August of that same year, Pope Clement VIII approved a Papal bull decreeing the annulment and secularization of the regular canons of the Order of Saint Augustine in all the monasteries and priories of Catalonia, Roussillon and Cerdanya, due to the dissolute life style of some communities of that order.
The pope commissioned the execution of the bull to the archbishop of Tarragona, the bishop od Urgel Andreu Capella (who was Terès's professor in theology) and the Apostolic Nuncio to Spain Pietro Millino.
Later, archbishop Terès sent his nephew and vicar general of the archdiocese of Tarragona, Antoni Clarassó i Terès, to read the bull to the canons gathered in Solsona.
From that moment on, they were left secularized and deprived of the canonical insignias.

While some monasteries had complied with the order of secularization, the monastery of Saint Mary of Solsona resisted, basing their reasons on the second Papal bull in which Clement VIII stated that if the canons demonstrated an exemplary behavior, they could continue enjoying their position and benefice.
The budget of the secularized monasteries went to Solsona.
Then, the Solsonians addressed to King Philip II to create a new diocese, with Solsona as the Episcopal see, using the new extended income and the monastery as a residence.
Once the pope agreed with the king's petition, Philip II informed of the approval of the Pope, and granted the ranked of city in 13 June 1594.

The creation of the diocese of Solsona caused serious unrest among the neighbouring dioceses because they saw their possessions diminished, especially in Urgel.
Terès, the bishop of Urgell and the new Apostolic Nuncio Camillo Caetani were commissioned to erect the new diocese.
After examining the life style and habits of the regular canons and declaring them free of guilt, they sent personal decrees to all of them, granting them the rights and benefice for their lifetime.
Finally, Terès took part in the formation of the cathedral chapter, and later, in the delimitation of the new diocese, together with the abbot of Poblet and President of Catalonia Francesc Oliver de Boteller.

In 18 September 1594, Terès travelled on board, escorted by eight galleys, to the island of Ibiza, then territory of the archdiocese of Tarragona.
During the trip, the expedition was assaulted by three Muslim pirate galleys.
Finally, the archbishop's galleys took over two pirate ships.

He protected several orders of friars, like the Capuchins, the Augustinians and the Carmelites, and he notably improved the monastery of the Jesuits.
While being archbishop he celebrated and presided the provincial ecumenical councils of 1587, 1591–92, 1598 y 1602.

On 4 April 1596, Terès proceeded to the recognition ceremony of the sepulcher of the Blessed Raymond of Penyafort, who later Terès promoted his canonization, by archbishop Terès, the bishop of Barcelona, Joan Dimas Loris,and the bishop of Vic, Pere Jaume, all three commissioned by Pope Clement VIII.
There were also present the bishop of Elne, Francesc Robuster i Sala, the recently appointed first bishop of Solsona, Lluís Sanç i Manegat, and the deputies of Catalonia and consuls of Barcelona.
Terès also promoted the beatification of the founder of the Society of Jesus, Ignatius of Loyola.

In 1602, the petronel-armed bandits Pere Voltor and
As archbishop, Terès founded the monastery of Saint Dominic in Ciutadilla, in 1588. He collaborated in the improvements of the monastery of Saint Mary of Bovera in Guimerà, and in the hermitage of Saint Magí of Brufaganya, near Santa Coloma de Queralt.
In 1589, he got for Tarragona the publication of the privilege of Studium Generale, granted by Philip II of Spain. This was celebrated with rejoicing and public festivities all around the city.
In 1591, Terès granted privileges of baptismal fonts to la Riba, due to the difficulty that represented for the villagers to go to Vilaverd.
In 1592, Terès ordered to build, in the cathedral of Tarragona, the chapels of Saint John the Evangelist and Saint Fructuosus, to the Renaissance architect Pere Blai.
In 13 August of that same year, Pope Clement VIII approved a Papal bull decreeing the annulment and secularization of the regular canons of the Order of Saint Augustine in all the monasteries and priories of Catalonia, Roussillon and Cerdanya, due to the dissolute life style of some communities of that order. The pope commissioned the execution of the bull to the archbishop of Tarragona, the bishop od Urgel Andreu Capella (who was Terès's professor in theology) and the Apostolic Nuncio to Spain Pietro Millino. Later, archbishop Terès sent his nephew and vicar general of the archdiocese of Tarragona, Antoni Clarassó i Terès, to read the bull to the canons gathered in Solsona. From that moment on, they were left secularized and deprived of the canonical insignias.
While some monasteries had complied with the order of secularization, the monastery of Saint Mary of Solsona resisted, basing their reasons on the second Papal bull in which Clement VIII stated that if the canons demonstrated an exemplary behavior, they could continue enjoying their position and benefice. The budget of the secularized monasteries went to Solsona. Then, the Solsonians addressed to King Philip II to create a new diocese, with Solsona as the Episcopal see, using the new extended income and the monastery as a residence. Once the pope agreed with the king's petition, Philip II informed of the approval of the Pope, and granted the ranked of city in 13 June 1594.
The creation of the diocese of Solsona caused serious unrest among the neighbouring dioceses because they saw their possessions diminished, especially in Urgel. Terès, the bishop of Urgell and the new Apostolic Nuncio Camillo Caetani were commissioned to erect the new diocese. After examining the life style and habits of the regular canons and declaring them free of guilt, they sent personal decrees to all of them, granting them the rights and benefice for their lifetime. Finally, Terès took part in the formation of the cathedral chapter, and later, in the delimitation of the new diocese, together with the abbot of Poblet and President of Catalonia Francesc Oliver de Boteller.
In 18 September 1594, Terès travelled on board, escorted by eight galleys, to the island of Ibiza, then territory of the archdiocese of Tarragona. During the trip, the expedition was assaulted by three Muslim pirate galleys. Finally, the archbishop's galleys took over two pirate ships.
He protected several orders of friars, like the Capuchins, the Augustinians and the Carmelites, and he notably improved the monastery of the Jesuits. While being archbishop he celebrated and presided the provincial ecumenical councils of 1587, 1591–92, 1598 y 1602.
On 4 April 1596, Terès proceeded to the recognition ceremony of the sepulcher of the Blessed Raymond of Penyafort, who later Terès promoted his canonization, by archbishop Terès, the bishop of Barcelona, Joan Dimas Loris,and the bishop of Vic, Pere Jaume, all three commissioned by Pope Clement VIII. There were also present the bishop of Elne, Francesc Robuster i Sala, the recently appointed first bishop of Solsona, Lluís Sanç i Manegat, and the deputies of Catalonia and consuls of Barcelona. Terès also promoted the beatification of the founder of the Society of Jesus, Ignatius of Loyola.
In 1602, the petronel-armed bandits Pere Voltor and 
Joan Terès i Borrull