diff --git a/python/core/core_auto.sip b/python/core/core_auto.sip
index a3ac0746017..981702a00ec 100644
--- a/python/core/core_auto.sip
+++ b/python/core/core_auto.sip
@@ -352,7 +352,6 @@
 %Include auto_generated/qgssnappingconfig.sip
 %Include auto_generated/qgstaskmanager.sip
 %Include auto_generated/qgstolerance.sip
-%Include auto_generated/qgstranslationcontext.sip
 %Include auto_generated/qgstrackedvectorlayertools.sip
 %Include auto_generated/qgstransaction.sip
 %Include auto_generated/qgstransactiongroup.sip
@@ -367,6 +366,7 @@
 %Include auto_generated/qgsvectorlayertools.sip
 %Include auto_generated/qgsvectorsimplifymethod.sip
 %Include auto_generated/qgssettings.sip
+%Include auto_generated/qgsprojecttranslator.sip
 %Include auto_generated/annotations/qgsannotation.sip
 %Include auto_generated/annotations/qgsannotationmanager.sip
 %Include auto_generated/annotations/qgshtmlannotation.sip
@@ -442,4 +442,5 @@
 %Include auto_generated/layertree/qgslayertreeregistrybridge.sip
 %Include auto_generated/qgsuserprofilemanager.sip
 %Include auto_generated/symbology/qgsarrowsymbollayer.sip
+%Include auto_generated/qgstranslationcontext.sip
 %Include auto_generated/qgsuserprofile.sip
diff --git a/src/app/qgsprojectproperties.cpp b/src/app/qgsprojectproperties.cpp
index 71f34b6ca09..e302ca39122 100644
--- a/src/app/qgsprojectproperties.cpp
+++ b/src/app/qgsprojectproperties.cpp
@@ -831,24 +831,23 @@ QgsProjectProperties::QgsProjectProperties( QgsMapCanvas *mapCanvas, QWidget *pa
   connect( titleEdit, &QLineEdit::textChanged, mMetadataWidget, &QgsMetadataWidget::setTitle );
 
   //fill ts language checkbox
-  //could possibly be taken from QgsOptions
-  QString myI18nPath = QgsApplication::i18nPath();
-  QDir myDir( myI18nPath, QStringLiteral( "qgis*.qm" ) );
-  QStringList myFileList = myDir.entryList();
-  QStringListIterator myIterator( myFileList );
-  while ( myIterator.hasNext() )
+  //fill ts language checkbox
+  QString i18nPath = QgsApplication::i18nPath();
+  QDir i18Dir( i18nPath, QStringLiteral( "qgis*.qm" ) );
+  const QStringList qmFileList = i18Dir.entryList();
+  for ( const QString &qmFile : qmFileList )
   {
-    QString myFileName = myIterator.next();
-
     // Ignore the 'en' translation file, already added as 'en_US'.
-    if ( myFileName.compare( QLatin1String( "qgis_en.qm" ) ) == 0 ) continue;
+    if ( qmFile.compare( QLatin1String( "qgis_en.qm" ) ) == 0 ) continue;
 
-    QString l = myFileName.remove( QStringLiteral( "qgis_" ) ).remove( QStringLiteral( ".qm" ) );
+    QString qmFileName = qmFile;
+    QString l = qmFileName.remove( QStringLiteral( "qgis_" ) ).remove( QStringLiteral( ".qm" ) );
 
     // QTBUG-57802: eo locale is improperly handled
     QString displayName = l.startsWith( QLatin1String( "eo" ) ) ? QLocale::languageToString( QLocale::Esperanto ) : QLocale( l ).nativeLanguageName();
     cbtsLocale->addItem( QIcon( QString( ":/images/flags/%1.svg" ).arg( l ) ), displayName, l );
   }
+
   cbtsLocale->addItem( QIcon( QString( ":/images/flags/%1.svg" ).arg( QStringLiteral( "en_US" ) ) ), QLocale( QStringLiteral( "en_US" ) ).nativeLanguageName(), QStringLiteral( "en_US" ) );
   cbtsLocale->setCurrentIndex( cbtsLocale->findData( settings.value( QStringLiteral( "locale/userLocale" ), QString() ).toString() ) );
 
diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 4fa40e3d88b..85edd65aeb2 100755
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -657,6 +657,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgswebpage.h
   qgswebview.h
   qgssettings.h
+  qgsprojecttranslator.h
 
   annotations/qgsannotation.h
   annotations/qgsannotationmanager.h
diff --git a/src/core/layertree/qgslayertreegroup.cpp b/src/core/layertree/qgslayertreegroup.cpp
index 80f61e6fc0b..31343107c47 100644
--- a/src/core/layertree/qgslayertreegroup.cpp
+++ b/src/core/layertree/qgslayertreegroup.cpp
@@ -255,7 +255,8 @@ QgsLayerTreeGroup *QgsLayerTreeGroup::findGroup( const QString &name )
 QList<QgsLayerTreeGroup *> QgsLayerTreeGroup::findGroups() const
 {
   QList<QgsLayerTreeGroup *> list;
-  Q_FOREACH ( QgsLayerTreeNode *child, mChildren )
+
+  for ( QgsLayerTreeNode *child : mChildren )
   {
     if ( QgsLayerTree::isGroup( child ) )
       list << QgsLayerTree::toGroup( child );
diff --git a/src/core/layertree/qgslayertreenode.cpp b/src/core/layertree/qgslayertreenode.cpp
index ec7ab4cd0d6..1a49e066926 100644
--- a/src/core/layertree/qgslayertreenode.cpp
+++ b/src/core/layertree/qgslayertreenode.cpp
@@ -65,6 +65,7 @@ QgsLayerTreeNode *QgsLayerTreeNode::readXml( QDomElement &element, const QgsProj
   if ( project )
     resolver = project->pathResolver();
   context.setPathResolver( resolver );
+  context.setProjectTranslator( ( QgsProject * )project );
 
   QgsLayerTreeNode *node = readXml( element, context );
   if ( node )
diff --git a/src/core/layout/qgscompositionconverter.cpp b/src/core/layout/qgscompositionconverter.cpp
index 16cbdeb1c78..122f641ef23 100644
--- a/src/core/layout/qgscompositionconverter.cpp
+++ b/src/core/layout/qgscompositionconverter.cpp
@@ -1193,6 +1193,7 @@ bool QgsCompositionConverter::readLegendXml( QgsLayoutItemLegend *layoutItem, co
     pathResolver = project->pathResolver();
   QgsReadWriteContext context;
   context.setPathResolver( pathResolver );
+  context.setProjectTranslator( ( QgsProject * )project );
 
   //composer map: use uuid
   QString mapId = itemElem.attribute( QStringLiteral( "map" ), QStringLiteral( "-1" ) );
diff --git a/src/core/qgslayerdefinition.cpp b/src/core/qgslayerdefinition.cpp
index 5d7bd48d0a7..83917a4c8a4 100644
--- a/src/core/qgslayerdefinition.cpp
+++ b/src/core/qgslayerdefinition.cpp
@@ -51,6 +51,7 @@ bool QgsLayerDefinition::loadLayerDefinition( const QString &path, QgsProject *p
 
   QgsReadWriteContext context;
   context.setPathResolver( QgsPathResolver( path ) );
+  context.setProjectTranslator( project );
 
   return loadLayerDefinition( doc, project, rootGroup, errorMessage, context );
 }
@@ -298,6 +299,7 @@ QList<QgsMapLayer *> QgsLayerDefinition::loadLayerDefinitionLayers( const QStrin
 
   QgsReadWriteContext context;
   context.setPathResolver( QgsPathResolver( qlrfile ) );
+  //no projecttranslator defined here
   return QgsLayerDefinition::loadLayerDefinitionLayers( doc, context );
 }
 
diff --git a/src/core/qgsproject.cpp b/src/core/qgsproject.cpp
index cc3789b65ce..5013dce7c53 100644
--- a/src/core/qgsproject.cpp
+++ b/src/core/qgsproject.cpp
@@ -861,6 +861,7 @@ bool QgsProject::_getMapLayers( const QDomDocument &doc, QList<QDomNode> &broken
     {
       QgsReadWriteContext context;
       context.setPathResolver( pathResolver() );
+      context.setProjectTranslator( this );
       if ( !addLayer( element, brokenNodes, context ) )
       {
         returnStatus = false;
@@ -960,6 +961,7 @@ bool QgsProject::read()
     }
 
     QgsReadWriteContext context;
+    context.setProjectTranslator( this );
     if ( !storage->readProject( filename, &inDevice, context ) )
     {
       QString err = tr( "Unable to open %1" ).arg( filename );
@@ -1107,6 +1109,7 @@ bool QgsProject::readProjectFile( const QString &filename )
 
   QgsReadWriteContext context;
   context.setPathResolver( pathResolver() );
+  context.setProjectTranslator( this );
 
   //crs
   QgsCoordinateReferenceSystem projectCrs;
@@ -1302,7 +1305,7 @@ bool QgsProject::readProjectFile( const QString &filename )
   emit ellipsoidChanged( ellipsoid() );
 
   // read the project: used by map canvas and legend
-  emit readProject( *doc );
+  emit readProject( *doc, context );
   emit snappingConfigChanged( mSnappingConfig );
 
   // if all went well, we're allegedly in pristine state
@@ -1537,6 +1540,7 @@ bool QgsProject::readLayer( const QDomNode &layerNode )
 {
   QgsReadWriteContext context;
   context.setPathResolver( pathResolver() );
+  context.setProjectTranslator( this );
   QList<QDomNode> brokenNodes;
   if ( addLayer( layerNode.toElement(), brokenNodes, context ) )
   {
@@ -2151,6 +2155,7 @@ bool QgsProject::createEmbeddedLayer( const QString &layerId, const QString &pro
   QgsReadWriteContext embeddedContext;
   if ( !useAbsolutePaths )
     embeddedContext.setPathResolver( QgsPathResolver( projectFilePath ) );
+  embeddedContext.setProjectTranslator( this );
 
   QDomElement projectLayersElem = sProjectDocument.documentElement().firstChildElement( QStringLiteral( "projectlayers" ) );
   if ( projectLayersElem.isNull() )
@@ -2207,6 +2212,7 @@ QgsLayerTreeGroup *QgsProject::createEmbeddedGroup( const QString &groupName, co
 
   QgsReadWriteContext context;
   context.setPathResolver( pathResolver() );
+  context.setProjectTranslator( this );
 
   // store identify disabled layers of the embedded project
   QSet<QString> embeddedIdentifyDisabledLayers;
diff --git a/src/core/qgsproject.h b/src/core/qgsproject.h
index 4da9f8945a8..dcab7e0fe64 100644
--- a/src/core/qgsproject.h
+++ b/src/core/qgsproject.h
@@ -997,7 +997,7 @@ class CORE_EXPORT QgsProject : public QObject, public QgsExpressionContextGenera
     /**
      * Emitted when a project is being read.
      */
-    void readProject( const QDomDocument & );
+    void readProject( const QDomDocument &, QgsReadWriteContext &context );
 
     /**
      * Emitted when the project is being written.
diff --git a/src/core/qgsprojecttranslator.h b/src/core/qgsprojecttranslator.h
index e87c3a6633d..2274204a3b8 100644
--- a/src/core/qgsprojecttranslator.h
+++ b/src/core/qgsprojecttranslator.h
@@ -37,6 +37,7 @@ class CORE_EXPORT QgsProjectTranslator
      *
      * \since QGIS 3.4
      */
+
     virtual QString translate( const QString &context, const QString &sourceText, const char *disambiguation = nullptr, int n = -1 ) const = 0;
 
     virtual ~QgsProjectTranslator() = default;
diff --git a/src/core/qgsreadwritecontext.cpp b/src/core/qgsreadwritecontext.cpp
index 4baa772c16e..7d2d2713a0a 100644
--- a/src/core/qgsreadwritecontext.cpp
+++ b/src/core/qgsreadwritecontext.cpp
@@ -14,6 +14,12 @@
  ***************************************************************************/
 #include "qgsreadwritecontext.h"
 
+QgsReadWriteContext::QgsReadWriteContext()
+  : mProjectTranslator( &mDefaultTranslator )
+{
+
+}
+
 QgsReadWriteContext::~QgsReadWriteContext()
 {
   // be sure that categories have been emptied
@@ -50,9 +56,22 @@ void QgsReadWriteContext::leaveCategory()
     mCategories.pop_back();
 }
 
+void QgsReadWriteContext::setProjectTranslator( QgsProjectTranslator *projectTranslator )
+{
+  mProjectTranslator = projectTranslator;
+}
+
 QList<QgsReadWriteContext::ReadWriteMessage > QgsReadWriteContext::takeMessages()
 {
   QList<QgsReadWriteContext::ReadWriteMessage > messages = mMessages;
   mMessages.clear();
   return messages;
 }
+
+QString QgsReadWriteContext::DefaultTranslator::translate( const QString &context, const QString &sourceText, const char *disambiguation, int n ) const
+{
+  Q_UNUSED( context );
+  Q_UNUSED( disambiguation );
+  Q_UNUSED( n );
+  return sourceText;
+}
diff --git a/src/core/qgsreadwritecontext.h b/src/core/qgsreadwritecontext.h
index b22c852484d..dee76979ecc 100644
--- a/src/core/qgsreadwritecontext.h
+++ b/src/core/qgsreadwritecontext.h
@@ -65,7 +65,7 @@ class CORE_EXPORT QgsReadWriteContext
     /**
      * Constructor for QgsReadWriteContext.
      */
-    QgsReadWriteContext() = default;
+    QgsReadWriteContext();
 
     ~QgsReadWriteContext();
 
@@ -106,7 +106,17 @@ class CORE_EXPORT QgsReadWriteContext
      */
     const QgsProjectTranslator *projectTranslator( ) const { return mProjectTranslator; }
 
+    void setProjectTranslator( QgsProjectTranslator *projectTranslator );
+
   private:
+
+    class DefaultTranslator : public QgsProjectTranslator
+    {
+        // QgsProjectTranslator interface
+      public:
+        QString translate( const QString &context, const QString &sourceText, const char *disambiguation, int n ) const;
+    };
+
     //! Pop the last category
     void leaveCategory();
 
@@ -114,8 +124,8 @@ class CORE_EXPORT QgsReadWriteContext
     QList<ReadWriteMessage> mMessages;
     QStringList mCategories = QStringList();
     QgsProjectTranslator *mProjectTranslator;
-
     friend class QgsReadWriteContextCategoryPopper;
+    DefaultTranslator mDefaultTranslator;
 };
 
 
diff --git a/src/core/qgsrelation.cpp b/src/core/qgsrelation.cpp
index 6af6c7a270c..ea761fdbb79 100644
--- a/src/core/qgsrelation.cpp
+++ b/src/core/qgsrelation.cpp
@@ -21,7 +21,7 @@
 #include "qgsproject.h"
 #include "qgsvectorlayer.h"
 
-QgsRelation QgsRelation::createFromXml( const QDomNode &node )
+QgsRelation QgsRelation::createFromXml( const QDomNode &node, QgsReadWriteContext &context )
 {
   QDomElement elem = node.toElement();
 
@@ -35,7 +35,7 @@ QgsRelation QgsRelation::createFromXml( const QDomNode &node )
   QString referencingLayerId = elem.attribute( QStringLiteral( "referencingLayer" ) );
   QString referencedLayerId = elem.attribute( QStringLiteral( "referencedLayer" ) );
   QString id = elem.attribute( QStringLiteral( "id" ) );
-  QString name = QgsProject::instance()->translate( QStringLiteral( "project:relations" ), elem.attribute( QStringLiteral( "name" ) ) );
+  QString name = context.projectTranslator()->translate( QStringLiteral( "project:relations" ), elem.attribute( QStringLiteral( "name" ) ) );
   QString strength = elem.attribute( QStringLiteral( "strength" ) );
 
   const QMap<QString, QgsMapLayer *> &mapLayers = QgsProject::instance()->mapLayers();
diff --git a/src/core/qgsrelation.h b/src/core/qgsrelation.h
index b50ac6aaf17..a61fe2e2175 100644
--- a/src/core/qgsrelation.h
+++ b/src/core/qgsrelation.h
@@ -22,6 +22,7 @@
 
 #include "qgis_core.h"
 #include "qgsfields.h"
+#include "qgsreadwritecontext.h"
 
 #include "qgis.h"
 
@@ -100,7 +101,7 @@ class CORE_EXPORT QgsRelation
      *
      * \returns A relation
      */
-    static QgsRelation createFromXml( const QDomNode &node );
+    static QgsRelation createFromXml( const QDomNode &node, QgsReadWriteContext &context );
 
     /**
      * Writes a relation to an XML structure. Used for saving .qgs projects
diff --git a/src/core/qgsrelationmanager.cpp b/src/core/qgsrelationmanager.cpp
index a0c6c722d24..81ca4b2e83a 100644
--- a/src/core/qgsrelationmanager.cpp
+++ b/src/core/qgsrelationmanager.cpp
@@ -153,7 +153,7 @@ QList<QgsRelation> QgsRelationManager::referencedRelations( QgsVectorLayer *laye
   return relations;
 }
 
-void QgsRelationManager::readProject( const QDomDocument &doc )
+void QgsRelationManager::readProject( const QDomDocument &doc, QgsReadWriteContext &context )
 {
   mRelations.clear();
 
@@ -165,7 +165,7 @@ void QgsRelationManager::readProject( const QDomDocument &doc )
     int relCount = relationNodes.count();
     for ( int i = 0; i < relCount; ++i )
     {
-      addRelation( QgsRelation::createFromXml( relationNodes.at( i ) ) );
+      addRelation( QgsRelation::createFromXml( relationNodes.at( i ), context ) );
     }
   }
   else
diff --git a/src/core/qgsrelationmanager.h b/src/core/qgsrelationmanager.h
index ac37a1d2e8c..9dfabf74c60 100644
--- a/src/core/qgsrelationmanager.h
+++ b/src/core/qgsrelationmanager.h
@@ -142,7 +142,7 @@ class CORE_EXPORT QgsRelationManager : public QObject
     void changed();
 
   private slots:
-    void readProject( const QDomDocument &doc );
+    void readProject( const QDomDocument &doc, QgsReadWriteContext &context );
     void writeProject( QDomDocument &doc );
     void layersRemoved( const QStringList &layers );
 
diff --git a/src/core/qgstranslationcontext.cpp b/src/core/qgstranslationcontext.cpp
index a39ca93635f..4e98848be5e 100644
--- a/src/core/qgstranslationcontext.cpp
+++ b/src/core/qgstranslationcontext.cpp
@@ -65,7 +65,7 @@ void QgsTranslationContext::writeTsFile( const QString &locale )
   tsElement.setAttribute( QStringLiteral( "sourcelanguage" ), settings.value( QStringLiteral( "locale/userLocale" ), "" ).toString() );
   doc.appendChild( tsElement );
 
-  for ( TranslatableObject translatableObject : mTranslatableObjects )
+  for ( const TranslatableObject &translatableObject : mTranslatableObjects )
   {
     QDomElement contextElement = doc.createElement( QStringLiteral( "context" ) );
     tsElement.appendChild( contextElement );