Thailand’s King Bhumibol Adulyadej, a prominent figure in the country who was seen as an important player in maintaining a balance of power in a volatile political climate, died Thursday after years of struggling with poor health.

The king, who was 88 when he died, will likely be succeeded by 63-year-old Crown Prince Vajiralongkorn. Vajiralongkorn, the late king’s son, is not as revered as his father in the eyes of the Thai public and could inherit a country that has been under military rule since 2014 when a coup was staged that some critics say King Adulyadej had been sympathetic with.

He will also inherit a fortune.

King Adulyadej was one of the richest monarchs on the planet with an estimated net worth between $30 and $40 billion (a 2016 estimate ranked Russian President Vladimir Putin as the only wealthier world leader). While it can be difficult to determine exactly how much the king is worth, numerous estimates over the years have placed the crown in that range.

Much of those wealth estimates come from property ownership. The monarchy sits on some prime real estate in Bangkok and central Thailand and leases out land or rents properties to subsidize rents. The king owns 3,320 acres in central Bangkok and another 13,200 acres in town and country holdings throughout the country. Just 7 percent of that land is fully leased on a commercial basis and those rents come out to around 4 percent of the market value of the land, which brought in about $80 million in 2010, according to estimates by Forbes.

The crown also has some valuable investments. The Crown Property Bureau (CPB), which manages the king’s properties and assets, maintained a 23 percent stake in the Siam Commercial Bank (Thailand’s largest bank that had a market cap of $23 billion in 2013) and 32 percent of the Siam Cement group, a $12.6 billion industrial company. Records and estimates show that those holdings allowed the CPB to collect $290 million in 2009, a time when the economy was hurting.