When British architect Leofric Kesteven sat down to design Selangor's royal mosque in the early 1920s, he faced a challenge that most architects would envy and dread in equal measure: create a building that honored Islamic tradition while satisfying a colonial administration steeped in European aesthetics. Kesteven, who chaired the Malayan Institute of Architects from 1921 to 1923, answered with something audacious. He blended Islamic architecture with Moorish, English, Neoclassical, and Art Deco influences into a single building. An Italian sculptor named Rodolfo Nolli, based in Singapore, carved the ornamental details, while reinforced concrete specialist John Thomas Chester ensured the structure would endure the tropical climate. The result, opened on 23 June 1923 by Sultan Sir Alaeddin Sulaiman Shah, was reportedly the largest mosque in the Federated Malay States.

Every dome on the Sultan Sulaiman Mosque carries meaning. The large semicircular dome over the main prayer space -- painted egg yellow, not gold -- represents the Sultan of Selangor. Four smaller domes surrounding it symbolize the Dato' Besar Empat Suku Selangor, the four great chiefs of the state. At the main entrance, five domes stand for the Five Pillars of Islam and the five Daeng Brothers, while two umbrella-shaped domes evoke the royal umbrella. Eight smaller towers encircle the mosque, with a larger central tower crowned by its own yellow dome. Viewed from above, Kesteven's original design followed a cruciform plan -- a layout borrowed from European church architecture. Later renovations by the Selangor Islamic Religious Department reshaped the footprint into a square, but the building's hybrid DNA remains legible in its silhouette.

For over six decades, the Sultan Sulaiman Mosque served as the state mosque of Selangor, the spiritual center of one of Malaysia's wealthiest states. That role ended in 1988 when the massive Sultan Salahuddin Abdul Aziz Mosque opened in Shah Alam, the new state capital. Rather than fading into obscurity, the Klang mosque became the royal mosque -- an intimate, more personal designation tied directly to the sultanate. Its grounds hold a royal mausoleum where four sultans rest, including Sultan Salahuddin Abdul Aziz Shah, who served as Malaysia's eleventh Yang di-Pertuan Agong. Royal consorts and prominent members of the Selangor royal family are also buried here. The Tangga Diraja, or royal stairs, connect the mosque to the nearby Istana Alam Shah, binding palace and prayer in stone.

The mosque has been renovated more than a dozen times since its opening -- in 1933, 1949, the 1950s, 1960s, 1970s, 1980s, 1990s, and 2000s. Each round of work added modern conveniences but also obscured original details. The most significant restoration came between March 2015 and October 2017, when the mosque closed entirely for a 12-million-ringgit conservation project. Workers peeled back layers of cement and white paint to reveal those seventy colorful bas-relief panels that had been hidden for years. The panels depict local flora and landscapes of the Klang District, rendered in hues that no other mosque in Malaysia shares. In May 2012, the building had already been declared a National Heritage Building, and the 2017 restoration aimed to return the mosque as close to Kesteven's original vision as possible -- a vision that turned out to be far more colorful than anyone remembered.

Before construction began in 1922, a ceremony was held to determine the mosque's qibla -- the precise direction toward the Kaaba in Mecca. Royalty, government officials, religious figures, British officers, and architects gathered to observe shadows cast by vertical objects, using this ancient astronomical method to orient the entire building. A century later, the Sultan Sulaiman Mosque still faces exactly where those shadows pointed. Klang, once the capital of Selangor before Kuala Lumpur overtook it, has grown into a busy port city around the mosque. But on the grounds where sultans are buried and bas-reliefs bloom in tropical color, the building holds its position -- pointed toward Mecca, anchored in a past that keeps revealing new layers.