During medieval times and for a long period after, il-Marsa was part of the parish of St George at Ħal Qormi (Città Pinto), until1913 when il-Marsa was declared a parish. It is said that in 1890 il-Marsa had a population of 6,200 souls and 200 houses, but the increased activity of the Port il-Ġdid (Portu Novu), il-Marsa began to grow into a suburb. After a steady growth, il-Marsa is undergoing a continued and pronounced decrease in population.
Deep inside the Gran Harbour there are the two creeks forming an area known as il-Marsa, most important since olden times. The word il-Marsa is an Arabic word meaning a place for anchorage and mooring of ships .
The inlet was also known as the two creeks (żewġ marsiet) one named Xatt il-Qwabar (Shore of brackish water crabs) and the other il-Marsa il-Kbira; (Larger il-Marsa), which stretches to the chapel Ċejlu;. It became to be known also as Portu Novu. The two creeks are separated by the Għolja tal-Giżwiti behind which lies the flat plain which stretches out to the outskirts of Ħal Qormi (Città Pinto). It is clear to see that land and the two valleys are in this area below sea level. These valleys, Wied is-Sewda and Wied il-Kbir, meander into this plain.
Long ago, even before the coming of the Knights of St John, this shallow creek stretched to the limits of Ħal Qormi (Città Pinto), places known as Taċ-Ċagħqi or l-Erba Qaddisin;. Since ancient times man seeking refuge in those areas used to cultivate fields and grow crops. The plain is said to have patches of simar, had a water channel full of ells, a water bed strewn with arched sea shells, and an inlet here fish were abundant. Archeological discoveries made in different parts of il-Marsa show that from ancient time this place was known by the people who lived in this country and learned how how to exploit the shelter offered by its creeks.