Gilleleje ['Gill-el-ay] is the conjunction of the Danish words Gil, which is a crevice or cleft and Leje, which is a place where fishermen come in specific seasons to fish. It was probably concatenated from Gilbjerg Leje, where Gilbjerg ("cleftmountain") is a rather dramatic name for a rather mundane point just east of town limits. The towns ending in -leje are often from the 16. century, when the fishermen actually settled and regular townships appeared. Compare with the Swedish ending läge. The city is located at the northernmost point of Sjælland (Zealand) in Denmark.
The earliest confirmed permanent residence in Gyldeleye (original spelling) is in the early 1500. An excavation done in 1979 by the city museum revealed the lot from a house under the layers of sand. The house had most likely been built shortly after 1536, as a coin was found, dated 1534-36. As there was also found ceramics reminiscent of other finds, it is assumed by the archeologists that the culturelayer is from the late 1400s. Additionally, the house was found on the address Fabersvej 10 which is not the closest to the beach, and the habit was to build from the beach and inwards.
At around this time, it is also known that the town had enough financial means to build a church and hire a priest. This required some money back then, and the general consensus, then, is that the town went from seasonal fishing to year round fishing, and the fishermen settled down in the years surrounding 1500. Town hall has established 1488 as the "official" founding year to make celebrating easier. The church was inaugurated in 1538 by the newly hired priest Hans Lauridtzen.
In 1588, the vassal of Kronborg made a list of the taxes that the fishermen should pay. This was one or a half barrel of codfish. From this list, we can see who the earliest citizens were (a goldmine for the amateur genealogist - if you think you've relatives in the area, I'd be happy to transcribe the list for you). There are about 70 names (a name is analogous to a house - think 500+ citizens), with the surnames Lauritsen, Rasmussen, Jensen and Skomager being the most common.
Aside from the fishing, the taxes allowed people to grow various crops south of the town, such as wheat. There was also a pasture, on which there was a few cows and sheep. Most of the town was on the eastern side of the stream that came from Søborg ("Lakecastle" - ironically, the lake has been drained and the castle is now a ruin) in the south and went out in the ocean just east of the drying ground.
Unfortunately, the influx of fishermen made hard on the fishing, and several families could not catch enough fish to both sustain a living and pay the taxes. In 1632, only 18 families were left. This stabilized the conditions somewhat, and in 1682, the number was up to 30, according to the records of Christian V. A new problem was present, though. The shifting sand would bury boats and nets, and had to be shoveled away, delaying the real work somewhat. Part of the eastern side of the town was even deserted as a few houses had gradually been buried under dunes.
South of the town was Nellerupgård, the local manor, home to Carl Christian Lembach and Catrine Marie Milan. They owned most of the land in the area, especially after extracting "their" parts of the common pasture, letting the ordinary Gillelejere get the furthermost areas.
During the 1810s and 20s, the city expanded a lot, and many new houses were built in the eastern area that had once been abandoned. A real harbor was built in 1873, where the drying ground had been. This meant larger ships and thus more jobs, making more people move to the town. In 1890, the town was at 865 households, 112 of which were fishermen.
The outer harbor was finished in 1902, and Gilleleje continued to thrive on its fishing until 1941 when the Germans occupied Denmark. As most other Danes at the time, the Gillelejere were against the oppresion and helped the Jews by hiding them various places in the town. However, on October 2, 1943, the Gestapo set out to capture all Danish Jews. The Jews in Gilleleje were hid on the church-loft, and the fishermen prepared for taking them across the sound to Sweden in their cutters. They could not leave immediately, though, because of the German patrols in the street. After several days of hiding, an informer let the Germans know where the roughly 75 Jews were hiding, and they were all captured, bar a single boy who hid behind a gravestone in the cemetary. My grandparents tell me the priest was so mortified by the situation that he never really became normal again. This was the single biggest capture the Germans managed to do (luckily, this was also one of the only).
After the occupation was over, several memorials have been put up in the town, both commemorating the Jews and the fishermen who lost their lives when colliding with seamines.
The eastern areas (called Stæremosen - "Starling moor") that had been used for pasture became the industrial area in and around 1950, creating more jobs, meaning more newcomers. The harbor is the 5th largest commercial fishing harbor in Denmark.
Sources: Johannes Steenstrup - De Danske Stednavne ("The Danish Placenames") of 1918, Palle Lauring - Her Skete Det 1: Sjælland ("It Happened Here 1: Zealand") of 1969, Various - Gilleleje: 1488 - 1988 of 1988, my history teacher, my memories, and most importantly, my maternal grandparents, Jógvan Julius Joensen and Ada Agnete Joensen née Andersen.