A square is controlled from both ends of the line on which it is on. During the solution, access to this square is blocked by closing the lines from both sides, which can be exploited.
The Island theme was extensively developed in the 1970s, particularly by the Hungarian composers György Páros (1910–1975), Arpád Molnár (1936–2012), and László Apró (1907–2000).
A confusion with the theme name: the English word "Island" translates to "Insel" in German, whereas the German "Island" translates to "Iceland" in English.
Alias: Iceland theme; Insel-Thema (Ger.).
Páros, György
Die Schwalbe, Carte de Voeux TT, 1949
1.Sc4
Kd1
2.Bg4
d4#
1.Sg4
Kf1
2.Bc4
f4#
Zarur, Almiro Elias
Dalla Rosa JT, 1964
1st Comm.
1.Sfe2
Sgf4
2.Se6
Se3#
1.Sfe6
Sdf4
2.Se2
Se3#
Páros, György
Budapesti Sakkszövetség TT, Magyar Sakkelet, 1965
1st Prize
1.Bb1
Re1
2.e5
Ke2#
1.Bf1
Bb1
2.f5
Kc2#
Páros, György
Magyar Sakkélet, 1974
1st Prize
a) 1.Ra3
f3
2.Bd4+
c3#
b) 1.Ra4
f4
2.Be3
c4#
Abdurahmanović, Fadil
British Chess Magazine, 1978
3rd Prize
1.Qf5
Bd5
2.Ke5
Qg7#
1.R4f3
Rad5+
2.Ke4
Rh4#
Budapesti Sakkszövetség TT, 1975
1st Prize
a) 1.Sf6
Rc3
2.Bf5
Sb5#
b) 1.Sb2
g7
2.Bb5
Sf5#