The Church and the Cloister of San Lorenzo, according to a plan already in posses of the monks, were built in 886, while a privilege of Aloara, brings it again to a following century, near the homonym Burgh, at the crossbreed of the street Consolare Campana (or Cumana) with the Antiqua.
            The convent, that greeted the Benedictines of the destroyed Cloister of San Vincenzo upon the Volturno, had an auspicious life since its rise by enjoying the concessions that made it rich and powerful. Some confirmations of Giordano on the law of fishing in the lake di Patria, the jurisdictions on the Cloister of San Biagio and the Church of Casolla Valenzana date from 1079. In addition the Abbots had the faculty to prevent some processions and celebrate distinctive functions without the authorization of the bishop and the Pope.
             In origin the church presented a plant similar to that of Cassino with the transept that included the three terminal apses, the crypt corresponding to the area of the presbytery and a portico opposite the façade where the fine marble porch (XII sec.) was put in whose epistyle the names of Abbot Matteo and the author Berardus author are related:

Hoc opus has valvas Matheus condidit abbas / Ingrediens portas cum / Xristum pectore portas / Quem petis exora tacit(a) vel voce sonora / Ut procul a pena requie patiatur amena / M. Berardus.

            In the XV and XVI centuries there were profound metamorphoses: the apses were remade in a square form and, the central one, preceded by a triumphal arc, two more naves were added and the convent was widened with two new cloister of which the big one by Andrea Ciccione in the half of the XV century; the work, on a double Tuscanian order, is one of the most beautiful of this type for the extreme lightness and the rational equilibrium of the structure, the other, with the diamond pit between two trabeated columns, presents square pillars.
            From the recent interventions of restauration trace of the cosmatesque paving circular weave bosses are emerged, with tarsias of colored stones, and in the central nave, in an inferior level, wall structures have appeared dating back to the III-II sec. d. C., ruins that indicate that the area ab antiquo was inhabited while, at an intermediary level, tombs of the high-medioeval period were abstracted. The high bell towner (XV sec.), that had to finish with a cusp, occupies part of the left presbytery.

           Il convento, che accolse anche i benedettini del distrutto Monastero di San Vincenzo al Volturno, ebbe vita prospera sin dal suo sorgere godendo di concessioni che lo resero ricco e potente. Al 1079 risalgono alcune conferme di Giordano sul diritto di pesca nel lago di Patria, le giurisdizioni sul Monastero di San Biagio e sulla Chiesa di Casolla Valenzana. Inoltre agli Abati fu concessa la facoltà di impedire alcune processioni e di celebrare funzioni particolari senza l'autorizzazione del vescovo e del papa.