Tengku Abdul Aziz, the eldest son of Sultan Hisamuddin took the throne following his father's death. He used the title Sultan Salahuddin Abdul Aziz Shah.[23] In 1974, he signed the 1974 Federal Territory of Kuala Lumpur Agreement which then established the Federal Territory in Malaysia.[24] Later, he commissioned the building of Kota Darul Ehsan arch to commemorate this event and as a border mark between Kuala Lumpur and Selangor.[25] After Kuala Lumpur was made Federal Territory, he proclaimed Shah Alam as the new capital of Selangor. The placed is named after his father, Sultan Hisamuddin Alam Shah.[26] His most notable legacy is the Sultan Salahuddin Abdul Aziz Mosque, the largest mosque in Malaysia.[27] Sultan Salahuddin was installed as the eleventh Yang di-Pertuan Agong in 1999 for two years until his death in 2001.[28]