diff --git a/Geant4/G4config/CMakeLists.txt b/Geant4/G4config/CMakeLists.txt
index e108e841b1c2394457331f7c7ada6677cd56af8f..9ff4e7b1f4d080e7847d60e5922582a7d7a84562 100644
--- a/Geant4/G4config/CMakeLists.txt
+++ b/Geant4/G4config/CMakeLists.txt
@@ -30,7 +30,7 @@ if (NOT GEANT4_TAG)
   elseif(CMAKE_PROJECT_VERSION STREQUAL "HEAD")
     # Special mapping of version HEAD
     # WARNING this must be kept up to date manually
-    set(GEANT4_TAG "lhcb/v10.3.3-branch")
+    set(GEANT4_TAG "lhcb/v10.4.1-branch")
   else()
     set(GEANT4_TAG lhcb/${CMAKE_PROJECT_VERSION})
   endif()
diff --git a/ReleaseNotes/v103r3.md b/ReleaseNotes/v103r3.md
new file mode 100644
index 0000000000000000000000000000000000000000..7adcbccd2bc8bd5f8dda370511001f2e7c01b5d9
--- /dev/null
+++ b/ReleaseNotes/v103r3.md
@@ -0,0 +1,9 @@
+2018-02-07 Geant4 v103r3
+===
+This version uses LCG 91 (Gaudi v29r0) and Geant4Files v103r1.
+
+This version is released on `Sim10` branch.
+
+This is the first LCHb release of Geant4 10, supports CMake, CMT support has been dropped.
+
+LHCb PhysLists and Tests have been extracted from the Geant4-src LHCb patches and now reside as separate packages under LHCbG4PhysLists and LHCbG4Tests.
diff --git a/ReleaseNotes/v104r1.md b/ReleaseNotes/v104r1.md
new file mode 100644
index 0000000000000000000000000000000000000000..2fa98308ef5ba8a5412578bacd4e25bcf3b208f4
--- /dev/null
+++ b/ReleaseNotes/v104r1.md
@@ -0,0 +1,19 @@
+2018-04-25 Geant4 v104r1
+===
+This version uses LCG 91 (Gaudi v29r0) and Geant4Files v104r0.
+
+This version is released on `Sim10` branch.
+
+## Latest Changes
+
+#### GEANT4
+
+Switched to Geant4 release `10.4.1`.
+
+#### LHCb G4 Physics Lists
+
+**[MR !31] Updated method name in PhysLists for 10.4.1**
+
+#### LHCb G4 Tests
+
+**[MR !31] Added new test G4GammaToDiLeptonConversionTest based on TestEm6**