I visit its museum one afternoon, hoping to learn more about the nawab, but there was only a portrait of him resplendent in flowing robes and turban.
This much is known, however. In 1890, the Duke of Clarence visited Junagadh and the nawab had trouble finding a lion for him to shoot. According to one count, there were just 12 left. He duly declared Gir a protected area, if only to ensure he still had some lions left to shoot.
In 1911, the nawab was succeeded by his son, Sir Muhammad Mahabat Khanji III, who loved animals so much that he owned 300 hugely pampered dogs. The museum has a portrait of him, sitting with a bejewelled dog at his feet.
The new nawab banned all shooting at Gir. He thus saved the lions, but failed to save himself. Being Muslim, he enraged his Hindu subjects by trying to lead Junagadh into the new state of Pakistan following India's partition in 1947. He was forced to flee to Karachi. There, he died - of rabies - in 1959.
By the time Gir was made an official sanctuary in 1965, it had about 170 lions and that number has continued to increase.
Today, there are more than 520. At least 150 of those now live outside the sanctuary and range across 20,720 sq km of bush and farmland.
In 2005, they became the first carnivores to have their conservation status downgraded from critically endangered to endangered by the International Union for the Conservation of Nature.
The Gujarat Forest Department has done its job well. In the 1970s, it moved thousands of traditional cattle herders called Maldharis out of Gir and resettled them elsewhere, triggering a sharp rise in the number of boar, deer and other animals on which the lions prey.
It employs about 300 dedicated rangers, many of them women dubbed "Queens of the Forest", who constantly track the lions armed only with sticks called lathis.
"It's a beautiful animal," says Ms Rasila Vadher, who heads one of three rescue teams that are on standby for calls from rangers or villagers about sick or injured lions. The teams bring about 100 lions a year to a state-of-the-art treatment centre at the park's headquarters, most of them injured in fights with other lions.
At the centre, she shows me a steel cage in which she has occasionally been lowered into wells to tranquillise and then extract lions that have fallen in.
I can hear some of the rescued lions in their curtained cages, but I am not allowed to see them lest I add to their trauma.
The forest department has also established several smaller, satellite sanctuaries. It has built walls around thousands of open wells so the lions do not fall in. It has fenced off many kilometres of railway lines after several lions were hit by trains and introduced a 20kmh speed limit on a line - replete with hand-operated signals and points - that passes though the sanctuary.
Funding is no object. As Gujarat's chief minister before becoming India's Prime Minister in 2014, Mr Narendra Modi ensured that the forest department had all the resources it needed.
That lavish funding means Gir can limit the number of tourists it admits each day. Inside the sanctuary, I see practically none.
But the lions also owe their resurgence to the people living in and around Gir.
They are vegetarian, so hunt neither the lions nor the animals they eat. They are extremely devout and the lion occupies a special place in the Hindu pantheon of living creatures as it is the animal on which the goddess Durga rides. More prosaically, the lions scare away the nilgai, boars and deer that eat the farmers' crops.
One day, I visit a "ness", one of the primitive settlements of the few hundred Maldharis who still live inside the sanctuary and survive by selling their cattle's milk and dung.
I meet Karim, a 70-year-old woman with a leathery face and gold nose ring. She lives in a mud-walled hut with numerous barefooted grandchildren, protected from Gir's wildlife only by a thorn fence.
She says her husband had twice been attacked by lions, both times when he was trying to protect his cattle, but insists: "The lions are like gods. They need food."
She is much more afraid of the sanctuary's many leopards and one 10-year-old grandson still bears the scars of a recent leopard attack on his face and neck.
Villagers outside the sanctuary express the same reverence. They do not mind if the lions sometimes kill their cattle, though this is a poor area where camel carts still outnumber tractors. Occasionally, they leave old or weak cows out for them.
"It's their right. This is the lions' land," says resident Bhupat Babuy Bhuvva whose village, Dhanej, loses three or four cows a month.
Once or twice a year, perhaps, the lions kill humans, but the villagers excuse them even for that. They know to steer clear when the lions are mating, hunting or having cubs and they can read the warning signs - the roar, the raised tail, the pawing at the ground. "Only when humans make mistakes do they get attacked," Ms Vadher, the rescue team leader, tells me.
Two years ago, a lioness killed one drunken youth and injured another near the village of Rajula, when they tried to take pictures of her two cubs on their mobile phones.
Dr Chavinath Pandey, formerly Gujarat's chief wildlife warden, went to the scene and met a female relative of the dead boy.
"She said the lioness was not at fault. Our children were at fault. The villagers didn't want the lioness taken away. I was amazed and moved," he tells me when we meet in the Nawab of Junagarh's former hunting lodge, now the forest department's guesthouse. "This is a place where the big cat and local people are in complete understanding with each other and, to my mind, that's the reason the lions are surviving so well."
What does dismay the villagers, however, is the death of a lion.
When 10 drowned in flash floods last summer, hundreds of people gathered in the village of Krankach, prayed before garlanded photos of the lions and pledged never to let such a disaster happen again.
When a lion, frightened by an oncoming car at night, jumped off a bridge near Sasan Gir and killed itself, the townspeople closed their businesses for a day to mourn.
Watching the lions sleeping peacefully in Gir that afternoon, I rejoice at a rare success in the usually bloody and depressing field of modern conservation.
The challenge the forest department now faces is how to prepare hundreds of villages further away from Gir for the likely arrival of lions in future years. It needs to teach the villagers to protect their cattle, avoid confrontations and co-exist with the animals.
Dr Pandey sees few limits on the lions' expanding habitat. He says there is enough food, water and shelter for them to move much further afield. "It's difficult to see a maximum limit... In 20 years' time, you might find lions around Ahmedabad," he says, to my astonishment.
That is more than 300km from Gir.