Flagging master as 1.0.0-pre1.
diff --git a/tools/distrib/python/grpcio_tools/grpc_version.py b/tools/distrib/python/grpcio_tools/grpc_version.py
index 4b1e7fc..7938b3d 100644
--- a/tools/distrib/python/grpcio_tools/grpc_version.py
+++ b/tools/distrib/python/grpcio_tools/grpc_version.py
@@ -29,4 +29,4 @@
# AUTO-GENERATED FROM `$REPO_ROOT/templates/tools/distrib/python/grpcio_tools/grpc_version.py.template`!!!
-VERSION='0.16.0.dev0'
+VERSION='1.0.0rc1'
diff --git a/tools/doxygen/Doxyfile.c++ b/tools/doxygen/Doxyfile.c++
index de7acd7..fa4b50f 100644
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@@ -40,7 +40,7 @@
# could be handy for archiving the generated documentation or if some version
# control system is used.
-PROJECT_NUMBER = 0.16.0-dev
+PROJECT_NUMBER = 1.0.0-pre1
# Using the PROJECT_BRIEF tag one can provide an optional one line description
# for a project that appears at the top of each page and should give viewer a
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 76bb3b6..1473594 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -40,7 +40,7 @@
# could be handy for archiving the generated documentation or if some version
# control system is used.
-PROJECT_NUMBER = 0.16.0-dev
+PROJECT_NUMBER = 1.0.0-pre1
# Using the PROJECT_BRIEF tag one can provide an optional one line description
# for a project that appears at the top of each page and should give viewer a
diff --git a/tools/doxygen/Doxyfile.core b/tools/doxygen/Doxyfile.core
index 53ae4e4..7619b95 100644
--- a/tools/doxygen/Doxyfile.core
+++ b/tools/doxygen/Doxyfile.core
@@ -40,7 +40,7 @@
# could be handy for archiving the generated documentation or if some version
# control system is used.
-PROJECT_NUMBER = 0.16.0-dev
+PROJECT_NUMBER = 1.0.0-pre1
# Using the PROJECT_BRIEF tag one can provide an optional one line description
# for a project that appears at the top of each page and should give viewer a
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index b846237..66d6156 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -40,7 +40,7 @@
# could be handy for archiving the generated documentation or if some version
# control system is used.
-PROJECT_NUMBER = 0.16.0-dev
+PROJECT_NUMBER = 1.0.0-pre1
# Using the PROJECT_BRIEF tag one can provide an optional one line description
# for a project that appears at the top of each page and should give viewer a