[1] A son of the Protestant father and Eastern Orthodox mother, Wołłowicz became a Catholic and was educated at the Jesuit Academy of Vilnius and the Pontifical Gregorian University in Rome and was ordained as a priest.

At the same time, entered the court of the Grand Duke Sigismund III Vasa becoming a referendary (a type of judge; 1600–1615), later royal secretary (1605–1615) and deputy chancellor (1615–1618).

In a 1625 report to the pope, he claimed that during his nine-year tenure as bishop, there were more than 40 new Catholic churches and 27 new monasteries established in the diocese.

Despite his reputation of a sincerely religious man, he was known for his tolerant attitude towards the Protestants and support of the Ruthenian Uniate Church.

During his ad limina visit to Rome in 1620–1621, Wołłowicz obtained papal approval for the feast of Saint Casimir and discussed the proposed new faculties of law and medicine at the Jesuit Academy of Vilnius.

He became subdeacon on 24 September 1594 at Trinità dei Monti and deacon on 13 April 1596 at the St. Mary's Chapel of the Pontifical Gregorian University.

[17] While peace was not achieved, he was sent in fall 1607 to Tyniec where rebellious Benedictines refused to accept new abbot appointed by the king.

A manuscript produced by a monk records his good deeds: he constructed the dormitory, commissioned the main altar with a tabernacle, gifted expensive church vestments and liturgical objects, transferred abbot's house in Poznań to the abbey, ordered repairs to monastery buildings, improved discipline, paid salary to an official tasked with resolving monastery's lawsuits, appointed visitators to oversee monks and provosts living outside the abbey, etc.

[23] Wołłowicz spent considerable amount of time outside of the Grand Duchy of Lithuania (about 20 years) and was more familiar with Polish dignitaries.

[29] After becoming bishop, he gave up only the office of the custodian of church property (custos) at Vilnius cathedral chapter, and continued as provost of Trakai and abbot of Lubiń.

[30] After his resignation in 1618, he organized a diocesan synod, visited churches in Vilnius, created Archdeaconry of White Ruthenia usually governed by the dean of Aboĺcy [be], and initiated construction of a house for retired clergy.

[19] Suffering from gout, Wołłowicz spent some time improving his health in hot springs of Padua where his ill second cousin Mikołaj Pac [pl], former Bishop of Samogitia, resided.

[36] Around 1618, Wołłowicz and Wawrzyniec Gembicki, Primate of Poland, signed an instruction for diplomatic envoys to Moscow during the Polish–Muscovite War (1605–1618).

[38] In a 1625 report to the pope, Wołłowicz claimed that made deaneries more active – deans visited their parishes every three months and called synods twice a year.

They survived in Antakalnis only with the help of Wołłowicz's successor Abraham Woyna as well as donations from Józef Korsak and Michał Kazimierz Pac.

[44] Wołłowicz was particularly supportive of the women Benedictines and helped them establish their monastery in Vilnius and take over the Church of Saint Nicholas in Kaunas.

[46] For some reason, Wołłowicz was not supportive of the Dominican Order and on a couple occasions delayed or denied his approval for their monasteries.

Together with his brother Hieronim Wołłowicz, he supported the plans to establish faculties of law and medicine at the Jesuit Academy in Vilnius.

Wołłowicz discussed the issue during his trip to Rome in 1620–1621 and Superior General Mutio Vitelleschi approved the faculties as an exception in early 1623.

[50] Wołłowicz also collected books – some of them bear inscriptions that they were gifts by the authors, such as Matthew Rader or Justus Lipsius.

[53] He also sponsored a Latin translations of a religious work by Pietro Giustinelli (published twice in 1624 and 1629) that was intended for the Lithuanian clergy.

[54] A religious booklet with prayers and recollections about Jesus Christ was published by a Franciscan friar in Padua in 1620 and was also dedicated to Wołłowicz.

[55] He also sponsored the publication of two non-religious books – a Polish-language sermon delivered by Mateusz Bembus [pl] during the funeral of the royal secretary Andrzej Bobola [pl] (published in 1629) and a Polish translation of a work by Marco Antonio de Dominis explaining his reasons for leaving England.

[59] When his brothers funded the Benedictine Monastery in Tytuvėnai, Wołłowicz gifted it with a painting of the Mother of God for the main altar and co-sponsored its church bell.

[58][61] He also likely gifted doors of a church tabernacle by Matthias Wallbaum [de], goldsmith from Augsburg, to Vilnius Cathedral.

[65] He organized construction of a house for retired and ill clergy; it was eventually built near the Church of the Holy Cross.

[66] Likely, he initiated or at least supported the establishment of a primitive hospital (Lithuanian: špitolė) of Joseph of Arimathea and Nicodem in Vilnius during the 1624–1625 plague outbreak.