Medieval Titchfield was a very busy place comparing favourably in wealth with many towns in other counties. Many immigrants from Kent, Sussex, Devon, Cornwall and northern Hampshire had settled here. By 1300 it had become a substantial town with a market and a population of at least 600. It was in the 100 years or so between the foundation of the abbey and the coming of the plague that Titchfield reached the highest point of population and prosperity in its history relative to other parts of the country. Many crafts and industries were carried out and this commercial activity brought the settlement of merchants, sailors and substantial freemen. In 1393 King Richard II and his Queen, Anne of Bohemia were presented with a petition of grievances by the villagers of Titchfield, who strongly denounced war and the oppressive taxes.

By the fourteenth century the parish boundary ran roughly from Curbridge along a small tributary of the Hamble River towards Shedfield, through Biddenfield to the River Meon near Knowle. It then followed the River to Hollam, turned sharp east between Fareham and Crofton to Hoe Ford on the Fareham to Gosport Road. The boundary then went south to Peel Common and followed the river Alver to the sea at Browndown. From here if returned to Curbridge and then along the sea shore and the east bank of the Hamble River. This boundary remained almost unchanged until the nineteenth century.

In the first half of the 14th century a chapel was added to the church on the south side of the chancel. The earliest monument in the church dates from this time. It is a much worn effigy of a knight in armour found at the east end of the South chapel.

The fifteenth century saw further changes. A fine aisle was added on the north side of the nave (possibly replacing an earlier aisle in the same position) and the chancel was extensively remodelled. It was probably during this century that the spire was added to the west tower.

It requires a considerable effort of imagination to visualise the interior of the church as it was at the end of the medieval period. For one thing we must imagine its colourfulness; we must restore in our minds the medieval stained glass in the windows, the murals on the blank spaces of walling, the altars with their rich hangings and their reredoses, the painted statues and the like.

The church must have had a number of altars, three at the very least; one in the chancel, one in the south chapel and one in the north aisle. There were probably also altars in the south aisle and in the nave on either side of the chancelarch. The altars in the north aisle and in the chancel, backed by large windows filled with stained glass and tiers of niches with painted statues, must have been particularly magnificent.

Arguments between the abbot and the tenants of Titchfield had been going on since about 12 years after the building of the abbey, because the abbot wanted more rent and services. Over the years this had caused many disputes. On one occasion it caused a scene in the church. When one of the bishop's officers stood up after mass on 23 December 1377 to announce the closure of a small chapel at Hook, the congregation shouted him down. The medieval ancestors of Titchfield showed their forthright character on many occasions.

In the 1340's the disease called plague, and commonly known as the Black Death spread rapidly across Asia and Europe to England. It was thought to be a result of the development of trade and agriculture and the movement of carts and ships loaded with grain .... and rats. Titchfield was probably one of the earliest places in England to be affected. By September 1348 it had reached Titchfield and large numbers of deaths were reported over that winter. Altogether the deaths of 123 Titchfield tenants were reported over the next two years, and since there were only about 150 tenants before the plague, the mortality may have been as high as 80%. Some families were totally wiped out before 1379, and their land went to other families when they took up the vacant holdings. People who survived the plague were generally better off, but the population was much lower, the market for all goods was smaller and there was a long period of economic depression.