Strambi preached missions - a focal point of the Passionist charism - and drew large crowds due to the effectiveness of his preaching. There were even several occasions where he preached before bishops and cardinals. In 1773 he was made a professor of theological studies at the order's house in Rome - at Santi Giovanni e Paolo - and it was here that he was present at the death of Paul of the Cross. The founder said to Strambi on his deathbed: "You will do great things! You will do great good!" It was after this that he occupied several high offices in the order such as the rector of the Roman house and the provincial for the Roman province. In 1784 he was relieved of these duties in order to write a biographical account of Paul of the Cross which was later published in London (Blessed Dominic Barberi wrote the preface). The Napoleonic invasion in the Papal States and the anti-religious decrees forced Strambi to flee Rome in 1798, though it was in vain as the French forces in May 1799 took him prisoner. He managed to return to Rome not long after this.