Along with François de Sales and Pierre de Bérulle, Vincent de Paul is one of thebest-known French Catholic reformers of the ‘century of saints’. He was the founder of the Ladies and Daughters of Charity, and the Congregation of the Mission, secular missionaries also known as the Lazarists after their mother house, the priory of St Lazarus, Paris. Using the extensive archive left by de Paul and the Congregation, particularly their correspondence, Forrestal examines the reformer's work, achievements, limitations and significance, fully contextualised in the extensive historiography of the Catholic Reformation in France. The result is a rich and finely crafted book.

Forrestal focuses on the development of the Lazarist order rather than the whole of de Paul's works. Her aims are to examine de Paul's efforts to create, characterise and articulate a distinctive vision for missionary life and work, both for himself and the Lazarist Congregation, in the French Church during this era. Forrestal warns us, however, to be wary of the term ‘mission’: de Paul used it in a specific way – to denote missionary activity – but also in a more traditional apostolic sense of being called by God to propagate the faith.

The structure of the book is initially chronological, then thematic. In part i, Forrestal examines de Paul's arrival in Paris in 1608 through to his foundation of the Lazarists in 1625 and their papal approval in 1633. Through the influence of de Bérulle, de Paul entered the household of the Gondi family, where he remained until 1625 – except for a time as priest at Châtillon-les-Dombes in 1617 – and where he took up rural pastoral work on their estates. Forrestal evaluates the impact of these experiences on his emerging sense of vocation: the priest as missionary sought to discover virtue by working with the peasantry and thus to move closer to God through them. His pastoral emphasis was on confession – especially general confession – and catechetical instruction, both linked to the primacy of the eucharist. Another feature of de Paul's pastorate in these years was the promotion of confraternities; from his time at Châtillon onwards he encouraged charitable action groups for lay women. Thus, the groundwork of his pastoral practice and piety was laid.

In part ii, Forrestal examines how de Paul translated his personal vocation into an organisation of missionaries whose function was to evangelise the rural poor. Through high-level patronage from the Gondi, Richelieu, de Sillery and other families, de Paul overcame financial and other obstacles to found and develop the Congregation of the Mission. This combined missionary work and community life, and was dedicated to priestly instruction and mission. There was a distinct and carefully cultivated Lazarist ethos, whose basis was ‘charitable love’. Salesian spirituality provided the glue which bound de Paul, his spiritual friends and patrons together.

Part iii focuses on the pastoral activities of the Congregation. Firstly, Saint-Lazare became an important college, retreat centre and site of the Tuesday Conferences of hand-picked seminarians, many of whom went on to influential positions in the French Church. Then, from 1635, de Paul founded houses outside Paris, mostly mission houses backed by wealthy lay patrons. After 1643 patronage shifted to the episcopate, for whom the training of priests was the priority. A robust model of clerical training was developed at the Lazarist mother house in Paris to provide disciplined clergy who were not theologians but pastoral priests and missionaries.

In part iv, confraternities are examined. De Paul realised early on the utility of confraternities as a means of organising, promoting and channelling female religious expression and incorporated their foundation into Lazarist missions. The Ladies and Daughters of Charity became the main way in which he engaged with lay women. These groups offered de Paul significant opportunities to undertake pastoral care in parishes, granting access to labour and resources which would otherwise not have been available to him. In chapter x Forrestal discusses the influence of de Paul on other confraternities, for example the Company of the Holy Sacrament which he joined in 1635. Overlapping membership between the female confraternities, the clergy of the Tuesday Conferences and the Company brought advantages such as assisting the foundation of a Congregation house in Marseilles in 1643.

Part v explores de Paul's influence on the French Church through his patronage networks. From 1643 to 1652 de Paul was a member of the royal Council of Ecclesiastical Affairs which appointed bishops, while the Richelieu family gave him direct rights of appointment over the benefices of two major abbeys and a priory. Finally, de Paul's antipathy towards the Jansenist movement is examined in the last chapter. De Paul considered Antoine Arnaud's On frequent communion to make false claims and to question magisterial authority, unhelpful for pastoral care and theologically unsound.

Forrestal concludes that de Paul stands out from his peers because he sculpted a distinctive and popular manifestation of religious activism within the French Catholic Reformation. He transformed a personal vocation into a Congregation of secular missionaries entrusted with multi-faceted features of pastoral care. It fostered lay piety through missions, improved standards and education of clergy through seminary training and spiritual retreats, and encouraged charitable welfare. De Paul was successful because he was good at forging attachments with patrons who could promote his missionary endeavour. Over time, he benefitted particularly from the patronage of female members of the nobility as well as bishops; he also came to the Crown's attention, which brought further resources and influence. In return, he provided services for his sponsors, clergy training, intelligence and the promotion of royal authority.

Overall, Forrestal has provided an excellent study of de Paul. Based on detailed research and a deep knowledge of seventeenth-century France, she reassigns agency to an individual who was a good strategist, while not downplaying the context in which he operated. She has provided a work which all historians of the Counter-Reformation should read.