As you can see, paintings with gold backgrounds prevail in the first few rooms of the National Gallery. Let me tell you about one of these: it is a jewel dating back to the last few years of the 14th century, and has been one of the most precious paintings in England for centuries.
It is an elegant diptych, which is a painting consisting of two panels held together by a hinge. It was made for King Richard II of England, but it is still unclear whether the artist who painted it was English or French: the tempera painting technique is connected to Italian art, but the white plaster background and use of an oak board as a support are typical features of Nordic art. The work is slightly larger than a manuscript and depicts a majestic royal ceremony: on the left panel you can see the King of England on his knees, accompanied by three royal patron saints (King Edmund, Edward the Confessor, and Saint John the Baptist) who present him to the "heavenly court" painted on the other panel. King Edmund holds one of the arrows that caused his death while fighting against the Danes in the ninth century, and Edward the Confessor, whose tomb Richard would pray at during times of crisis, shows a ring: according to legend he gave the ring to a pilgrim who later revealed himself as Saint John the Evangelist. The presence of Saint John the Baptist is instead tied to Richard II's date of birth: January 6th, the day when the Church celebrates the baptism of Christ.
On the right side of the diptych you can see the blooming garden of Paradise, which is a symbol of Mary's purity: the Virgin looks at the kneeling donor, and the baby Jesus reaches forward as if accepting the king's prayers. An angel holds the standard of the Resurrection, white with a red cross, which is also the flag of England: in short, Richard receives a sort of divine "investiture".
FUN FACT: if you look at the painting very closely, you'll see many details in the hidden coats of arms: the angels of the heavenly court bear the sign of the king, a white deer with golden horns, and are wearing broom-wood necklaces. You can also see the same broom-wood crowns and deer in the ornamental motifs of King Richard's clothes.