Epigraphic, funeral and numismatic witnesses show that present-day territory of Tordandrea was settled in the Roman age (but, surely, even in older times). The first medieval archives show the presence of Longobard civilization. On the other hand, it has been shown that the duchy of Spoleto extended its western edges till the river Chiascio, setting under its influence the whole zone in which Tordandrea was going to be built.
In the years between eleventh and twelfth centuries, there was a large estate, which included Fratticciola (Castelnuovo, at the present day), owned by Lupo, Count Monaldo's son. Monaldo was one of the most powerful men of that times in this portion of Umbria, and, maybe, heir of an ancient Longobard family. In the list of the many little settlements of Assisi municipality, written down in 1232, Tordandrea does not exist. We can say, however, that such a territory was under control of Costano, S. Costanzo, Castelnuovo and Valecchie. In the territory depending from Costano was, for instance, a little church dedicated to St. Simeone, passed, in later times, under Torre d'Andrea, and still later under S. Quirico di Bettona. Torre d'Andrea does not appear either among the sites listed in Assisi's statutes of 1469, simply because at that time, Torre d'Andrea did non belong to Assisi's municipality. The name Turris, mentioned in the land register of goods and churches in the archive of St. Rufino and in a legal act of 1413, maybe refers to Tordandrea; in the same register we read that Turris belongs to the site of Costano.


    The erudite Francesco Antonio Frondini from Assisi, reports the presence, in Tordandrea, of an important stone inscription, in gothic types, which he had seen "on the left of the tower's door". Thus, the tower around which the castle was going to be built just a century later, and named Tordandrea, seems to have been built in 1297, even if Cristofani attributes the above inscription to one of the many medieval house-towers of the city. The oldest documented report about the existence of a so-called "Torre d'Andrea" is around 1395. In that year, indeed, for the first time we find mentioned "Palazzo d'Andrea". His owner, Andrea Paolo degli Abati or Abbati, is told by Frondini to be "powerful lord in Assisi which built a stronghold, or a castle, in the plain of Assisi, and for this reason called Torre d'Andrea".


    The first fact about the settlers of this fort is an agreement drawn up in Assisi in the presence of two witnesses, in front of S. Lucia's Chapel in the Church of S. Paolo, situated at the bottom of Piazza Grande on the 11th of may 1427. That day assembled fourteen men from Torre d'Andrea di Paolo dell'Abbate of Assisi. Those men, in the name of other seven absent citizens, swore on the Gospel to stand an "order", divided in several chapters. Among these chapters there was the prior one, about the need to consolidate and restore the fort, for the purpose of making it safer from possible intrusions or assaults from armed people, and other kind of dangers for its citizens.


    The most important fact in the first half of '400 in the history of Torre d'Andrea is its fortification done for defence purposes by joining the external walls of the houses till they became a single wall - castle's body. One could access inside this wall only through the main door, still existent, with a raising bridge over the moat around the castle. During that year, on may the 13th, in the presence of two witnesses and a public notary, thirteenth men gathered to appoint three citizens (Luca di Giovanni di Ghibellino, Lorenzo di Sante and Andrea di Vanni) "to build and to make build the fort's walls and any other thing necessary to the repair and the fortification of that place, and to elect the keepers of the door, which, every evening, have to bring back the keys to the tower's keeper".


Abbati's coat of arms

    Before of the above-mentioned, another Andrea is documented in year 1335. As usual, Frondini remembers us that Corrado, Andrea's son, became bishop of Assisi in 1329. To tell the truth, in the same period, we have knowledge of a certain Andrea di Paolo, monk in the abbey of St. Benedict, on Mount Subasio, and later passed to a site in the diocese of Gualdo Tadino in which, in 1328, he founded the Congregation of the Body of Christ with Cistercian constitutions and the rule of St. Benedict of Norcia. He became the first general abbot, and in the same place he died with "fame of goodness" in 1344. Would it be the same person? If so, we would face a monk with sons that he has had before (meaningful to think) embracing the Benedictine order. In this context, the nickname "The Abbot", maybe attached to him and then to his heirs till it became a surname (Abbati or Abati), would find its explanation by means of his high religious rank. About the other Andrea - the one who lived between the end of thirteen and the first half of fourteen centuries - we know that his father, a citizen of Assisi, dead before August 1409, was named Paolo too, and his mother was a certain Massaria, which, once widow, entered the Third Order of Continent Women of St. Francis and she became abbess of it. It is known, moreover, that the second Andrea di Paolo, called "The Abbot", owned in Assisi a kitchen garden and a house to clean up the wool dresses, situated in Porta Santa Chiara, near the homonymous convent, from which it was separated by a ditch, were flowed the dirty water. It is known, furthermore, that in 1415-16 Andrea degli Abbati had a lawsuit with Ludovico Amatucci (Andrea's daughter Gabriella married Evangelista, son of Ludovico). Apart from Gabriella, Andrea had another son, Marchese or Marchesino, owner of a mill inside Assisi's walls, commonly called "the mill of the marquis of the abbot". Marchese di Andrea, which in an act of 1476 figures as executor of a certain Brigida, Antonio di Michele's daughter, had three sons: Cesare, Giacomo and Andrea. This last Andrea, improperly called "de Marchesi" from Cristofani (instead of "di Marchese"), had an important role in the history of Assisi in the middle of the fourteenth century.