Before the darkness fell on it, Honeythumbs were the ones who passed through lands and came to Enedwaith. They were distant relatives of Brandybucks, so you can guess that they were as adventurous as Brandybucks at worst.
After settling in Enedwaith, just by Maur Tulhau they started examining all the caverns and ruins nearby, even sometimes in deep corners of the country. In years, with all those discoveries (note that almost all Honeythumbs became either a treasure hunter or a trader) their wealth grew. For five hundreds years they kept growing up memberwise too and the little burrow they chose as a home for themselves at the beginning, became a large mansion, where lived around sixty hobbits.
During their discoveries, Saelo's grand-grand-grand father, Emmar Honeythumb found a brooch in a shape of eagle and a beryl inlayed on it. It was shining more than other things he found, therefore instead of adding it to the list of wares, he gave the brooch to his wife, Asella Honeythumb. And since that day, every eldest son of the family inherited the brooch from their mothers, then gave to the lass they chose as a wife.
This tradition continued till the day Alcash, a trader from Bree, came with a bid for the brooch. He was doing business with Saelo's grandfather, Adren, since years and in one of the visits he saw the heirloom, started eagerly wish it. Adren declined every bid of Alcash, which it became irritating at some point. Therefore one day Adren decided to speak straightforward with Alcash, instead of dealing with his every bid. "Alcash," he said, "ye're a good lad to do business with. Yet, I ask ye not to come with any bid for the brooch. Cause it's our family heirloom and not even a treasure can pay for it. This is the last time I talk about it and will no more. Ye're welcome for anythin' in me manor, except for the brooch."
After these words an expression of anger appeared in Alcash's eyes but he said nothing about it. Yet, Adren was concerned about what he saw, also all those tries for the brooch made him feel uncomfortable. Therefore he sent the brooch to the elves of Rivendell. Elves examined it and it turned out that the beryl on the heirloom had powers, which could lead disasters in wrong hands. They replaced the stone with another beryl cut in the same shape and sent it back to Adren. This eased his concerns in the heart.
But, once a shadow raises over something, it is not easy to totally get rid of it. After a few month, the heirloom gone missing. Adren knew whom to blame, but Alcash didn't visit him next year and neither the followed. At the end, he had to accept what fate brings and continued his life.
But it was not that easy to go on. Cause everything became dull and happiness was driven away from the mansion after that incident. Yet, it was not the worst happened. When Saelo was three years old, a large group of brigands attacked to the mansion at midnight. Robbed everything they found and killed whoever they saw. Only five survived: Saelo, his sister, mother and father, cause they were away from mansion fortunately. And Dolemer Honeythumb, Saelo's cousin was found one of the spirits protecting her the next day.
There is no point to reflect the whole story here. Shortly, Saelo's family moved to Bree after the incident and Dolemer was sent to his father of mother. After a few years, both of the Saelo's parents died in the hands of goblins. And only three Honeythumbs remained, far from each other and longing for the day of meet, if it happens.