Martin was noticed by Tremere in New York because of his adept skill at acquiring the support of political power to help his business concerns. He'd learned long ago that the real money was in the government, not in pure capitalism. Subsidies, grants, special protection, and the right sorts of regulation were much more profitable than competition any time. Inheriting a failing import/export company, he shocked his relatives by disassembling the family business and using the resultant capital to invest in more lucrative markets.
A skilled social player, he ingratiated himself with local politicians and learned who could be bought and who could merely be persuaded and turned his company into an unqualified success with the support of his new patrons in city government. The Tremere who took note approached the man and offered to give him the chance to practice his talents on a bigger field. Being a right greedy bastard, Martin accepted and adjusted very quickly to his new life. Only slightly stifled by the structure of the Tremere, he soon learned the political games he needed to play for power and advancement and mastered them.
Martin's move to Louisiana was recognition of a golden opportunity. With the Sabbat broken, the chance to seize a place for himself was too tempting. He came and settled in the modest town of Lake Charles, changing his surname to LaSalle in order to ingratiate himself with the locals. He established several businesses and political interests, which he controls still through subsidiaries, stock holdings, and strategically placed ghouls. After a decade or two, he used acquired favors and a little blackmail to get advanced to the rank of Regent so that he might set up his own chantry. Thus was the Dark Water Chantry born, with the begrudging support of the Tremere and the full support of Baton Rouge.
In the intervening years, the chantry has suffered a lot from the conflict between sects. Sabbat raids are fairly common and the Prince of Baton Rouge is growing more demanding in his requests for magical aid in his ongoing struggle with New Orleans. There has been a bit of a respite since the raid on Lafayette in 1970, which Martin took an active role in, tired of the revenant incursions into Lake Charles and looking for a means to advance himself politically by proving his effectiveness in combatting the Sabbat, and the lull in hostilities, but within the last twenty years two apprentices have gone missing and Martin is beginning to worry that there may be a traitor or a spy in the chantry.
Martin is a duplicitous, lazy man who has spent a life and a century and a half of unlife finding easier ways to get what he wants. He is the embodiment of the principle of getting the most from the least effort. His attitude his masked in the guise of a ruthless competitor in the political and economic spheres, but any close examination of his actions will show that his efforts are mostly illusory, merely him taking credit for the work of his ghouls or his apprentices or a scheme to cheat money or status out of another.
He's stopped being able to really mask his true intentions well as the years have passed and he comes off as sleazy and artificial most of the time, even when he's trying to ingragiate himself with someone. Thus, he's had to rely more and more on threats, intimidation, and his disciplines as his ability to persuade has left him. Also counting against him is his attitude towards Thaumaturgy, which he takes a great interest in, but only as a hobby. Lacking in the discipline to pursue it with any sort of serious dedication, he has alienated himself from many in his clan and his chances of further advancement are considerably limited.
Martin has a very distant relationshp with his apprentices. He considers them, for the most part, as part of his 'hobby', and thus spends a lot of time with them in thaumaturgical pursuits but doesn't allow them any contact with his political concerns or his businesses. This condescension is not overlooked by the twins.
Martin's grown increasingly annoyed with Orlando over the years, though he does all he can to keep up the facade of a good relationship, playing the loyal vassal. He is, however, toying with the concept of usurping the man's position and taking Baton Rouge for himself, realizing that his chances of further advancement in his clan is so severely limited by his casual attitude towards magic.
Most of Martin's interests lie in the petrochemical industry, which he was fortunate enough to get in at the beginning of, with some limited money in shipping and the import/export trade. He leaves much of the latter to Lafitte, however, willing to put his resources at the disposal of the more ambitious player and quietly take credit for his accomplishments.
He has also managed, over the years, to put himself in a good position with the local government, supplementing his legal and financial perks with well placed ghouls in key positions in the city government. His control is rather impressive in the city itself and he has been very successful in keeping Sabbat influences out while reinforcing his own advantage.