The King’s Indian Defence is probably the most romantic response to 1.d4.
It has survived the test of time and has been played at the highest level even to the present day.

Black gives his opponent complete freedom of choice in how to control the center and just develops quietly within his King’s Indian household, relying on his powerful fianchettoed bishop.

From the preface by Victor Bologan:

"This book is dedicated to a remarkable man, my “life-long” coach Zigurds Lanka, who uncovered for me the mysteries of the King’s Indian Defence!(..)

"The King’s Indian Defence is a living entity and is in a state of constant development. The evaluations of its various lines change constantly and sometimes quite dramatically at that. (..)

"The book is written for chess players of all levels, since the principles of the
King’s Indian Defence are equally applicable to the amateurs as well as to
the super-grandmasters."

Index of variations:

Part 1. Minor Variations
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7
1 4.Bg5
2 4.Nf3 0-0 5.Bg5
3 4.Nf3 0-0 5.Bf4
4 4.e4 d6 5.Bg5
5 4.e4 d6 5.h3 0-0 6.Bd3
6 4.e4 d6 5.h3 0-0 6.Be3
7 4.e4 d6 5.h3 0-0 6.Bg5
8 4.e4 d6 5.h3 0-0 6.Nf3
9 4.e4 d6 5.Nge2
10 4.e4 d6 5.Bd3

Part 2. Averbakh Variation
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 0-0 6.Bg5
11 6...Na6
12 6...h6

Part 3. Saemisch Attack
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 0-0
13 6.Nge2
14 6.Bg5
15 6.Be3 c5 7.dc
16 6.Be3 c5 7.d5; 7.Nge2

Part 4. Four Pawns’ Attack
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 0-0 6.Nf3 c5
17 7.Be2; 7.dc
18 7.d5 e6 8.de; 8.Be2 ed 9.cd Bg4
19 7.d5 e6 8.Be2 ed 9.cd Re8

Part 5. Classical Variation
1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 6.Be2 e5
20 7.de; 7.0-0 Nc6 8.de
21 7.Be3 Ng4
22 7.d5 a5
23 7.0-0 Nc6 8.Be3 Ng4; 8.d5 Ne7 9.Bg5; 9.Bd2; 9.Be3; 9.a4
24 7.0-0 Nc6 8.d5 Ne7 9.b4 Nh5
25 7.0-0 Nc6 8.d5 Ne7 9.Ne1 Nd7
26 7.0-0 Nc6 8.d5 Ne7 9.Nd2 c6
27 7.0-0 Nc6 8.d5 Ne7 9.Nd2 a5

Part 6. Fianchetto System
1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 0-0 5.Bg2 d6 6.0-0 Nc6
28 7.d5; 7.Nc3 a6 without 8.h3, 8.d5, 8.h3
29 7.Nc3 a6 8.h3 Bd7
30 7.Nc3 a6 8.d5 Na5
31 7.Nc3 a6 8.b3 Rb8

Other Fianchetto Systems

Double Fianchetto for White
32 1.Nf3 Nf6 2.g3 g6 3.b3 Bg7 4.Bb2 d6 5.d4 c5

Fianchetto without c2-c4 and Nc3
33 1.Nf3 Nf6 2.g3 g6 3.d4 Bg7 4.Bg2 0-0 5.0-0 d6

King’s Indian English
34 1.c4 Nf6 2.Nc3 g6 3.g3 Bg7 4.Bg2 0-0 5.e4; 5.0-0

Grandmaster Victor Bologan has won more than 40 international tournaments. His trophy list includes New York Open 1997, Aeroflot Open 2003, Dortmund 2003, Mainz 2002 and 2007. He has a Ph.D. in pedagogy. 

Victor Bologan wrote the bestselling books Victor Bologan: Selected Games 1985- 2004 (2006), and The Chebanenko Slav According to Bologan (2008).