diff --git a/merge-ort.c b/merge-ort.c
index 01f150ef3b..4302e900ee 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -387,6 +387,9 @@ struct merge_options_internal {
 
 	/* call_depth: recursion level counter for merging merge bases */
 	int call_depth;
+
+	/* field that holds submodule conflict information */
+	struct string_list conflicted_submodules;
 };
 
 struct version_info {
@@ -517,6 +520,7 @@ enum conflict_and_info_types {
 	CONFLICT_SUBMODULE_NOT_INITIALIZED,
 	CONFLICT_SUBMODULE_HISTORY_NOT_AVAILABLE,
 	CONFLICT_SUBMODULE_MAY_HAVE_REWINDS,
+	CONFLICT_SUBMODULE_NULL_MERGE_BASE,
 
 	/* Keep this entry _last_ in the list */
 	NB_CONFLICT_TYPES,
@@ -570,6 +574,8 @@ static const char *type_short_descriptions[] = {
 		"CONFLICT (submodule history not available)",
 	[CONFLICT_SUBMODULE_MAY_HAVE_REWINDS] =
 		"CONFLICT (submodule may have rewinds)",
+	[CONFLICT_SUBMODULE_NULL_MERGE_BASE] =
+		"CONFLICT (submodule no merge base)"
 };
 
 struct logical_conflict_info {
@@ -686,6 +692,8 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
 
 	mem_pool_discard(&opti->pool, 0);
 
+	string_list_clear(&opti->conflicted_submodules, 1);
+
 	/* Clean out callback_data as well. */
 	FREE_AND_NULL(renames->callback_data);
 	renames->callback_data_nr = renames->callback_data_alloc = 0;
@@ -1744,26 +1752,40 @@ static int merge_submodule(struct merge_options *opt,
 
 	int i;
 	int search = !opt->priv->call_depth;
+	int sub_initialized = 1;
 
 	/* store fallback answer in result in case we fail */
 	oidcpy(result, opt->priv->call_depth ? o : a);
 
 	/* we can not handle deletion conflicts */
-	if (is_null_oid(o))
-		return 0;
 	if (is_null_oid(a))
-		return 0;
+		BUG("submodule deleted on one side; this should be handled outside of merge_submodule()"); 
 	if (is_null_oid(b))
-		return 0;
+		BUG("submodule deleted on one side; this should be handled outside of merge_submodule()");
 
-	if (repo_submodule_init(&subrepo, opt->repo, path, null_oid())) {
+	if ((sub_initialized = repo_submodule_init(&subrepo,
+									opt->repo, path, null_oid()))) {
 		path_msg(opt, CONFLICT_SUBMODULE_NOT_INITIALIZED, 0,
 			 path, NULL, NULL, NULL,
 			 _("Failed to merge submodule %s (not checked out)"),
 			 path);
+		/*
+		 * NEEDSWORK: Since the steps to resolve this error are
+		 * more involved than what is currently in 
+		 * print_submodule_conflict_suggestion(), we return
+		 * immediately rather than generating an error message
+		 */
 		return 0;
 	}
 
+	if (is_null_oid(o)) {
+		path_msg(opt, CONFLICT_SUBMODULE_NULL_MERGE_BASE, 0,
+			 path, NULL, NULL, NULL,
+			 _("Failed to merge submodule %s (no merge base)"),
+			 path);
+		goto cleanup;
+	}
+
 	if (!(commit_o = lookup_commit_reference(&subrepo, o)) ||
 	    !(commit_a = lookup_commit_reference(&subrepo, a)) ||
 	    !(commit_b = lookup_commit_reference(&subrepo, b))) {
@@ -1849,7 +1871,15 @@ static int merge_submodule(struct merge_options *opt,
 
 	object_array_clear(&merges);
 cleanup:
-	repo_clear(&subrepo);
+	if (!opt->priv->call_depth && !ret) {
+		struct string_list *csub = &opt->priv->conflicted_submodules;
+
+		string_list_append(csub, path)->util =
+				xstrdup(repo_find_unique_abbrev(&subrepo, b, DEFAULT_ABBREV));
+	}
+
+	if (!sub_initialized)
+		repo_clear(&subrepo);
 	return ret;
 }
 
@@ -4412,6 +4442,73 @@ static int record_conflicted_index_entries(struct merge_options *opt)
 	return errs;
 }
 
+static void print_submodule_conflict_suggestion(struct string_list *csub) {
+	if (csub->nr > 0) {
+		struct string_list_item *item;
+		struct strbuf msg = STRBUF_INIT;
+		struct strbuf tmp = STRBUF_INIT;
+
+		strbuf_addf(&tmp, _("Recursive merging with submodules currently only supports trivial cases."));
+		strbuf_addf(&msg, "%s\n", tmp.buf);
+		strbuf_release(&tmp);
+
+		strbuf_addf(&tmp, _("Please manually handle the merging of each conflicted submodule."));
+		strbuf_addf(&msg, "%s\n", tmp.buf);
+		strbuf_release(&tmp);
+
+		strbuf_addf(&tmp, _("This can be accomplished with the following steps:"));
+		strbuf_addf(&msg, "%s\n", tmp.buf);
+		strbuf_release(&tmp);
+
+		for_each_string_list_item(item, csub) {
+			const char *abbrev= item->util;
+			/*
+			 * TRANSLATORS: This is a line of advice to resolve a merge conflict
+			 * in a submodule. The second argument is the abbreviated id of the
+			 * commit that needs to be merged.
+			 * E.g. - go to submodule (sub), and either merge commit abc1234"
+			 */
+			strbuf_addf(&tmp, _("go to submodule (%s), and either merge commit %s"),
+													item->string, abbrev);
+			strbuf_addf(&msg, _(" - %s"), tmp.buf);
+			strbuf_addf(&msg, "\n");
+			strbuf_release(&tmp);
+			strbuf_addf(&tmp, _("or update to an existing commit which has merged those changes"));
+			strbuf_addf(&msg, _("   %s"), tmp.buf);
+			strbuf_addf(&msg, "\n");
+			strbuf_release(&tmp);
+		}
+		strbuf_addf(&tmp, _("come back to superproject and run:"));
+		strbuf_addf(&msg, _(" - %s"), tmp.buf);
+		strbuf_addf(&msg, "\n\n");
+		strbuf_release(&tmp);
+
+		strbuf_addf(&tmp, "git add ");
+		strbuf_add_separated_string_list(&tmp, " ", csub);
+		strbuf_addf(&msg, _("       %s"), tmp.buf);
+		strbuf_addf(&msg, "\n\n");
+		strbuf_release(&tmp);
+
+		strbuf_addf(&tmp, _("to record the above merge or update"));
+		strbuf_addf(&msg, _("   %s"), tmp.buf);
+		strbuf_addf(&msg, "\n");
+		strbuf_release(&tmp);
+
+		strbuf_addf(&tmp, _("resolve any other conflicts in the superproject"));
+		strbuf_addf(&msg, _(" - %s"), tmp.buf);
+		strbuf_addf(&msg, "\n");
+		strbuf_release(&tmp);
+
+		strbuf_addf(&tmp, _("commit the resulting index in the superproject"));
+		strbuf_addf(&msg, _(" - %s"), tmp.buf);
+		strbuf_addf(&msg, "\n");
+		strbuf_release(&tmp);
+
+		printf("%s", msg.buf);
+		strbuf_release(&msg);
+	}
+}
+
 void merge_display_update_messages(struct merge_options *opt,
 				   int detailed,
 				   struct merge_result *result)
@@ -4461,6 +4558,8 @@ void merge_display_update_messages(struct merge_options *opt,
 	}
 	string_list_clear(&olist, 0);
 
+	print_submodule_conflict_suggestion(&opti->conflicted_submodules);
+
 	/* Also include needed rename limit adjustment now */
 	diff_warn_rename_limit("merge.renamelimit",
 			       opti->renames.needed_limit, 0);
@@ -4657,6 +4756,7 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 	trace2_region_enter("merge", "allocate/init", opt->repo);
 	if (opt->priv) {
 		clear_or_reinit_internal_opts(opt->priv, 1);
+		string_list_init_nodup(&opt->priv->conflicted_submodules);
 		trace2_region_leave("merge", "allocate/init", opt->repo);
 		return;
 	}
diff --git a/t/t6437-submodule-merge.sh b/t/t6437-submodule-merge.sh
index c253bf759a..414597a420 100755
--- a/t/t6437-submodule-merge.sh
+++ b/t/t6437-submodule-merge.sh
@@ -103,8 +103,25 @@ test_expect_success 'setup for merge search' '
 	 echo "file-c" > file-c &&
 	 git add file-c &&
 	 git commit -m "sub-c") &&
-	git commit -a -m "c" &&
+	git commit -a -m "c")
+'
 
+test_expect_success 'merging should conflict for non fast-forward' '
+	test_when_finished "git -C merge-search reset --hard" &&
+	(cd merge-search &&
+	 git checkout -b test-nonforward-a b &&
+	  if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	  then
+		test_must_fail git merge c >actual &&
+		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
+	 	grep "$sub_expect" actual
+	  else
+		test_must_fail git merge c 2> actual
+	  fi)
+'
+
+test_expect_success 'finish setup for merge-search' '
+	(cd merge-search &&
 	git checkout -b d a &&
 	(cd sub &&
 	 git checkout -b sub-d sub-b &&
@@ -129,14 +146,16 @@ test_expect_success 'merge with one side as a fast-forward of the other' '
 	 test_cmp expect actual)
 '
 
-test_expect_success 'merging should conflict for non fast-forward' '
+test_expect_success 'merging should conflict for non fast-forward (resolution exists)' '
 	(cd merge-search &&
-	 git checkout -b test-nonforward b &&
+	 git checkout -b test-nonforward-b b &&
 	 (cd sub &&
 	  git rev-parse --short sub-d > ../expect) &&
 	  if test "$GIT_TEST_MERGE_ALGORITHM" = ort
 	  then
-		test_must_fail git merge c >actual
+		test_must_fail git merge c >actual &&
+		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
+	 	grep "$sub_expect" actual
 	  else
 		test_must_fail git merge c 2> actual
 	  fi &&
@@ -161,7 +180,9 @@ test_expect_success 'merging should fail for ambiguous common parent' '
 	 ) &&
 	 if test "$GIT_TEST_MERGE_ALGORITHM" = ort
 	 then
-		test_must_fail git merge c >actual
+		test_must_fail git merge c >actual &&
+		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
+		grep "$sub_expect" actual
 	 else
 		test_must_fail git merge c 2> actual
 	 fi &&
@@ -205,7 +226,12 @@ test_expect_success 'merging should fail for changes that are backwards' '
 	git commit -a -m "f" &&
 
 	git checkout -b test-backward e &&
-	test_must_fail git merge f)
+	test_must_fail git merge f >actual &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+    then
+		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-d)" &&
+		grep "$sub_expect" actual
+	fi)
 '
 
 
@@ -476,4 +502,44 @@ test_expect_failure 'directory/submodule conflict; merge --abort works afterward
 	)
 '
 
+# Setup:
+#   - Submodule has 2 commits: a and b
+#   - Superproject branch 'a' adds and commits submodule pointing to 'commit a'
+#   - Superproject branch 'b' adds and commits submodule pointing to 'commit b'
+# If these two branches are now merged, there is no merge base
+test_expect_success 'setup for null merge base' '
+	mkdir no-merge-base &&
+	(cd no-merge-base &&
+	git init &&
+	mkdir sub &&
+	(cd sub &&
+	 git init &&
+	 echo "file-a" > file-a &&
+	 git add file-a &&
+	 git commit -m "commit a") &&
+	git commit --allow-empty -m init &&
+	git branch init &&
+	git checkout -b a init &&
+	git add sub &&
+	git commit -m "a" &&
+	git switch main &&
+	(cd sub &&
+	 echo "file-b" > file-b &&
+	 git add file-b &&
+	 git commit -m "commit b"))
+'
+
+test_expect_success 'merging should fail with no merge base' '
+	(cd no-merge-base &&
+	git checkout -b b init &&
+	git add sub &&
+	git commit -m "b" &&
+	test_must_fail git merge a >actual &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+    then
+		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short HEAD^1)" &&
+		grep "$sub_expect" actual
+	fi)
+'
+
 test_done
diff --git a/t/t7402-submodule-rebase.sh b/t/t7402-submodule-rebase.sh
index 8e32f19007..ebeca12a71 100755
--- a/t/t7402-submodule-rebase.sh
+++ b/t/t7402-submodule-rebase.sh
@@ -104,7 +104,7 @@ test_expect_success 'rebasing submodule that should conflict' '
 	test_tick &&
 	git commit -m fourth &&
 
-	test_must_fail git rebase --onto HEAD^^ HEAD^ HEAD^0 &&
+	test_must_fail git rebase --onto HEAD^^ HEAD^ HEAD^0 >actual_output &&
 	git ls-files -s submodule >actual &&
 	(
 		cd submodule &&
@@ -112,7 +112,12 @@ test_expect_success 'rebasing submodule that should conflict' '
 		echo "160000 $(git rev-parse HEAD^^) 2	submodule" &&
 		echo "160000 $(git rev-parse HEAD) 3	submodule"
 	) >expect &&
-	test_cmp expect actual
+	test_cmp expect actual &&
+	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+    then
+		sub_expect="go to submodule (submodule), and either merge commit $(git -C submodule rev-parse --short HEAD^0)" &&
+		grep "$sub_expect" actual_output
+	fi
 '
 
 test_done
