Unbreakable Soldiers Series by Megan Derr

Lord Vellem is a man desperate for escape. His father hides from his problems in alcohol, his mother hides from her misery in drugs, and his brother fled to the relative safety of the royal palace. Vellem eventually found solace in the Royal Army Corp of Engineers, but still could not entirely escape. Then his brother provides him with an unexpected chance, and now Vellem's marriage to the young prince of a neighboring kingdom is only months away... moreLord Vellem is a man desperate for escape. His father hides from his problems in alcohol, his mother hides from her misery in drugs, and his brother fled to the relative safety of the royal palace. Vellem eventually found solace in the Royal Army Corp of Engineers, but still could not entirely escape. Then his brother provides him with an unexpected chance, and now Vellem's marriage to the young prince of a neighboring kingdom is only months away. The marriage promises not just a fresh start in a new land, but a challenge to his famed skills in building roads and bridges. But before he can settle into his new life, tragedy strikes, and Vellem isn't certain he's up to rebuilding the ruin left in its wake. less

Prince Istari has spent his life reviled: his parents wish he had never been born, the royal court of Belemere avoids him for fear of angering the king, and everyone else is kept away by his notorious reputation as a deadly sharpshooter. Now a hostage of peace in Tallideth, he is subjected to their hatred as well—even that of Regent Vellem, who once considered him a comrade in arms... morePrince Istari has spent his life reviled: his parents wish he had never been born, the royal court of Belemere avoids him for fear of angering the king, and everyone else is kept away by his notorious reputation as a deadly sharpshooter. Now a hostage of peace in Tallideth, he is subjected to their hatred as well—even that of Regent Vellem, who once considered him a comrade in arms. Unexpected solace comes in the form of Lord Teverem, a sad, quiet lord who assumed the title when his brother was killed in the explosion for which Istari's father is to blame. He is kind and sweet and a sorely needed bright spot in Istari's life—until Istari meets his family and learns of a dangerous family secret with unexpected ties to Istari's past, a secret that could drag Tallideth and Belemere right back into war… ♦ 89,000 words WARNING: Attempted suicide less

Morrin has waited a long time to claim his throne, and even longer to have a real family. It may not be a conventional family, consisting of his closest friends, his brother Istari, and Istari's spouse and children, but it's one he loves and is proud of. No odious brothers, no abusive father, no cowardly mother... moreMorrin has waited a long time to claim his throne, and even longer to have a real family. It may not be a conventional family, consisting of his closest friends, his brother Istari, and Istari's spouse and children, but it's one he loves and is proud of. No odious brothers, no abusive father, no cowardly mother. The very last thing he wants is to upset the balance by taking a wife, but his friends are right in that seeing him married will go a long way toward repairing the damage caused by his war-mongering, tyrant father. He just didn't expect them to suggest the blandest princess in the castle. less

Bertin is a liar and a thief. Once an orphan on the street stealing purses, his life was forever changed when he saved a boy's life—and then became that boy to the rest of the world. But one lie always leads to another, and life as a Belemeren spy planted in the Engineer Corp has led him to the role of liaison in Ruemri, a kingdom he helped Ruemri's enemies steal.His primary duty is to watch King Sesta, which means he is himself watched by the whole of Ruemri's royal court... moreBertin is a liar and a thief. Once an orphan on the street stealing purses, his life was forever changed when he saved a boy's life—and then became that boy to the rest of the world. But one lie always leads to another, and life as a Belemeren spy planted in the Engineer Corp has led him to the role of liaison in Ruemri, a kingdom he helped Ruemri's enemies steal.His primary duty is to watch King Sesta, which means he is himself watched by the whole of Ruemri's royal court. For a man used to being overlooked and ignored, the situation is a living nightmare. That situation is further worsened when he receives word of an unspecified terrible event that is going to take place—and then the last person he expected arrives, bringing Bertin's past and secrets with him. less