Know much about him?
I like this story about him from the Catholic Encyclopedia:
It was on the occasion of the foundation of the convent of Prague (1601) that St. Lorenzo was named chaplain of the Imperial army, then about to march against the Turks. The victory of Lepanto (1571) had only temporarily checked the Moslem invasion, and several battles were still necessary to secure the final triumph of the Christian armies. Mohammed III had, since his accession (1595), conquered a large part of Hungary. The emperor, determined to prevent a further advance, sent Lorenzo of Brindisi as deputy to the German princes to obtain their cooperation. They responded to his appeal, and moreover the Duke of Mercœur, Governor of Brittany, joined the imperial army, of which he received the effective command. The attack on Albe-Royal (now Stulweissenburg) was then contemplated. To pit 18,000 men against 80,000 Turks was a daring undertaking and the generals, hesitating to attempt it, appealed to Lorenzo for advice. Holding himself responsible for victory, he communicated to the entire army in a glowing speech the ardour and confidence with which he was himself animated. As his feebleness prevented him from marching, he mounted on horseback and, crucifix in hand, took the lead of the army, which he drew irresistibly after him. Three other Capuchins were also in the ranks of the army. Although the most exposed to danger, Lorenzo was not wounded, which was universally regarded as due to a miraculous protection. The city was finally taken, and the Turks lost 30,000 men. As however they still exceeded in numbers the Christian army, they formed their lines anew, and a few days later another battle was fought. It always the chaplain who was at the head of the army. “Forward!” he cried, showing them the crucifix, “Victory is ours.” The Turks were again defeated, and the honour of this double victory was attributed by the general and the entire army to Lorenzo.
Let Pope Benedict tell you something more
Here is what the Martyrologium Romanum has:
Sancti Laurentii de Brundusio, presbyteri et Ecclesiae doctoris, inter Fratres Minores Capuccinos adscriptus, praedicandi munere in Europae regionibus indefesse functus est, tum pro Ecclesia defensione adversus infideles, tum in reconciliandis principibus, tum in Ordinis sui moderatione, omnia munera explens simplicitate et humilitate. Die vero vigesimo secundo iulii Ulyssipone in Lusitania obiit.