Idomeneo is not lost at sea, but instead is saved by Neptune (god of the sea) and is washed up on a Cretan beach. There he remembers the promise he made to Neptune: he had promised to sacrifice (kill for the Gods) the first creature he should meet, whether it be a human or an animal. The first person he meets is his own son, Idamante. Because the two have not seen each other for a long time, they do not recognize one another at first. When Idomeneo finally realizes it is his own son he must kill, he tells Idamante to go away and never see him again. Idamante does not understand why his father is saying this. He is terribly upset, but runs off. The Cretan soldiers get off Idomeneo's ship and are met by their wives, and all praise Neptune.
At the king's palace, Idomeneo asks Arbace what he should do, because he has disobeyed the god. Arbace says that Neptune would be happy if another victim could be sacrificed so long as Idamante is sent into exile (to another country). Idomeneo tells his son to take Electra to her home, Argos. Idomeneo's kind words to Ilia make her say very kindly that, because she has lost everything, he will be her father and Crete will be her country. As she leaves, Idomeneo realizes that sending Idamante into exile has made Ilia unhappy. Electra is happy about going to Argos with Idamante.
At the port of Sidon, Idomeneo says goodbye to his son and tells him to rule like a good king. Before the ship can sail, however, a storm breaks out, and a sea serpent appears. It is a messenger from Neptune, who is angry with Idomeneo. Idomeneo offers his life to the god.
In the royal garden, Ilia asks the gentle winds to carry her love to Idamante. Idamante says he must go to fight the serpent. When he says he would like to die because Ilia does not love him. This makes Ilia tell him that she loves him. They are surprised by Electra and Idomeneo. When Idamante asks his father why he sends him away, Idomeneo cannot tell him the truth. Ilia asks Electra for some kindness, but Elektra is madly jealous of Ilia now, and she wants revenge. Arbace comes with news that the people, led by the High Priest of Neptune, are shouting that they want Idomeneo. The High Priest tells the king that Neptune's monster is destroying things, and asks Idomeneo to say the name of the person whose sacrifice is demanded by the god. When the king says that his own son is the victim, the people are horrified.
Outside the temple, the king and High Priest join with Neptune's priests to pray that the god will be kind and merciful. Arbace brings news that Idamante has killed the monster. Idomeneo is now worried that Neptune will want even more revenge. Idamante enters in sacrificial robes, saying he understands his father's terrible worries and he is ready to die., Idomeneo says a tragic goodbye to his own son and is about to kill him, when Ilia steps forward and offers to die instead. Neptune now changes his mind. We hear his voice saying that if Idomeneo gives up being king and lets Idamante and Ilia rule as king and queen, he will forgive. Everyone is happy except Electra, who wants to die. Idomeneo says that Idamante and his bride are the new rulers. The people call upon the god of love and marriage to bless the royal pair and bring peace.
Lontzen
Lontzen is a municipality in the Belgian province of Liège.
In 2007, 5175 people lived there.
It is at 50° 40 North, 06° 00 East.
Lovendegem
Lovendegem is a former municipality in the Belgian province of East Flanders. On 1 January 2019, Lovendegem, Waarschoot and Zomergem were merged into the new municipality of Lievegem.
In 2007, 9393 people lived there.
It is at 51° 05 North, 03° 36 East.
Lubbeek
Lubbeek is a municipality in the Belgian province of Flemish Brabant.
In 2007, 13,740 people lived there.
It is at 50° 52 North, 04° 50 East.
Lummen
Lummen is a municipality in the Belgian province of Limburg.
In 2007, 13,803 people lived there.
It is at 50° 59 North, 05° 11 East.
Maarkedal
Maarkedal is a municipality in the Belgian province of East Flanders.
In 2007, 6460 people lived there.
It is at 50° 49 North, 03° 39 East.
Maaseik
Maaseik is a municipality in the Belgian province of Limburg.
In 2007, 23879 people lived there.
It is at 51° 05 North, 05° 47 East.
Maasmechelen
Maasmechelen is a municipality in the Belgian province of Limburg.
In 2011, 37,159 people lived there.
It is at 50° 58 North, 05° 41 East.
Machelen
Machelen is a municipality in the Belgian province of Flemish Brabant.
In 2007, 12792 people lived there.
It is at 50° 54 North, 04° 26 East.
Maldegem
Maldegem is a municipality in the Belgian province of East Flanders.
In 2007, 22366 people lived there.
It is at 51° 12 North, 03° 26 East.
Malle
Malle () is a municipality in the Belgian province of Antwerp.
In 2007, 14158 people lived there.
It is at 51° 17 North, 04° 41 East.
Malmedy
Malmedy is a municipality in the Belgian province of Liège.
In 2007, 11878 people lived there.
It is at 50° 25 North, 06° 01 East.
Manage
Manage is a municipality in the Belgian province of Hainaut.
In 2007, 22382 people lived there.
It is at 50° 30 North, 04° 14 East.
Manhay
Manhay is a municipality in the Belgian province of Luxembourg.
In 2007, 3185 people lived there.
It is at 50° 17 North, 05° 40 East.
Marche-en-Famenne
Marche-en-Famenne is a municipality in the Belgian province of Luxembourg.
In 2007, 17066 people lived there.
It is at 50° 13 North, 05° 20 East.
Marchin
Marchin is a municipality in the Belgian province of Liège.
In 2007, 5143 people lived there.
It is at 50° 27 North, 05° 14 East.
Martelange
Martelange is a municipality in the Belgian province of Luxembourg.
In 2007, 1584 people lived there.
It is at 49° 49 North, 05° 44 East.
Mechelen
Mechelen is a municipality in the south part of the Belgian province of Antwerp.
In 2007, 78,900 people lived there. In 2008: 80,176.
It is at 51° 01 North, 04° 28 East.
Meerhout
Meerhout is a municipality in the Belgian province of Antwerp.
In 2007, 9463 people lived there.
It is at 51° 07 North, 05° 04 East.
Meeuwen-Gruitrode
Meeuwen-Gruitrode is a former municipality in the Belgian province of Limburg. On 1 January 2019, Meeuwen-Gruitrode and Opglabbeek were merged into the new municipality of Oudsbergen.
In 2007, 12611 people lived there.
It is at 51° 05 North, 05° 31 East.
Meise
Meise is a municipality in the Belgian province of Flemish Brabant.
In 2007, 18545 people lived there.
It is at 50° 56 North, 04° 19 East.
Meix-devant-Virton
Meix-devant-Virton is a municipality in the Belgian province of Luxembourg.
In 2007, 2675 people lived there.
It is at .
Melle
Melle is a municipality in the Belgian province of East Flanders.
In 2007, 10660 people lived there.
It is at 51° 00 North, 03° 48 East.
Menen
Menen is a municipality in the Belgian province of West Flanders.
In 2007, 32439 people lived there.
It is at 50° 47 North, 03° 07 East.
Merbes-le-Château
Merbes-le-Château is a municipality in the Belgian province of Hainaut.
In 2007, 4141 people lived there.
It is at 50° 19 North, 04° 09 East.
Merchtem
Merchtem is a municipality in the Belgian province of Flemish Brabant.
In 2007, 15053 people lived there.
It is at 50° 57 North, 04° 14 East.
Merelbeke
Merelbeke is a municipality in the Belgian province of East Flanders.
In 2007, 22423 people lived there.
It is at 50° 59 North, 03° 44 East.
Merksplas
Merksplas is a municipality in the Belgian province of Antwerp.
In 2007, 8270 people lived there.
It is at 51° 21 North, 04° 51 East.
Mesen
Mesen is a municipality in the Belgian province of West Flanders.
In 2007, 983 people lived there.
It is at 50° 45 North, 02° 54 East.
Messancy
Messancy is a municipality in the Belgian province of Luxembourg.
In 2007, 7466 people lived there.
It is at 49° 35 North, 05° 49 East.
Mettet
Mettet is a municipality in the Belgian province of Namur.
In 2007, 12037 people lived there.
It is at 50° 19 North, 04° 39 East.
Meulebeke
Meulebeke is a municipality in the Belgian province of West Flanders.