Canon Background
https://awoiaf.westeros.org/index.php/Petyr_Baelish

In-Campaign
During the later days of 283AC Petyr accompanied his father to Castle Snownook to petition Lord Jasper for a position within his house. The lord’s son spoke favorably of a match (from a conversation he had with Petyr’s father while they attended the dual in Riverrun earlier in the year. Petyr spoke of having learned: not to think with his heart, talents with coin and information, and not to challenge a larger man to a duel as lessons he learned during his time as a ward of House Tully. He was pleased when all parties agreed that he should be given the position of steward of House Jasper on a probationary basis.

After several months of service Teddy shared with Calaila, Dolins, and Teddy that he had received troubling news from his father (in the presence of Lord Ronnel and Lady Alys. A rogue knight wearing the Jasper sigil has been terrorizing House Baelish’s lands.

Petyr was called to an audience with Ronnel, Alys, several household members, and some newcomers from House Elesham. Lord Ronnel inquired as to the state of the house’s finances and abilities to host annual grand tournaments (this outrageous expense had apparently been promised to a Ser Yoren). Petyr informed him that sadly a single grand tournament would nearly bankrupt the house; yearly tournaments were out of the question.

He testified at the trial of Ser Gyles at Snownook in 284 AC. He spoke of receiving a raven from his lord father and of urging Lord Jasper to dispatch a force to bring the knight to justice. He stated that Gyles acted on orders from Lord Yoren. The trial resulted in Gyles being found guilty and House Lynderly being punished. Following the conclusion of the trial, Petyr and his father were brought to audience with Jon Arryn and the Jaspers. Due to his merit and competencies as steward of House Jasper Petyr was offered the opportunity to travel to the capital with Jon and Lysa Arryn and serve as an advisor there. He smugly accepted.

At the wedding of King Robert and Queen Cersei. Petyr gained some coin from Ser Carsen when the former bet on Sandor Clegane and the latter bet on Ser Darron during the semi-finals of the joust. He was present in the Tower of the Hand when Jon Arryn appointed House Jasper as Marshall of the FIngers and the Isles on the day Robert Baratheon wed Cersei Lannister. He stood with his father and smiled smugly at the appointment.

Petyr met with Teddy and Jardon in the solar of the Tower of the Hand with Jon Arryn in the days after the royal wedding. They requested Lord Arryn’s support in gaining entrance to the Red Keep’s library to find a map as they are sailing in search of treasure. Jon agreed and at Petyr’s suggestion imposed a 20% tax for the crown on the treasure.

Petyr later attended the tournament at Snownook in 285 AC celebrating House Jasper’s new title. While watching the melee unfold with his father, Teddy Jasper approached. After some small talk Petyr reminded Teddy of taxes owed to the crown. Teddy (falsely) claimed to have recovered a lone dragon egg in Valyria . Petyr recommended he seek a merchant in the capital named Caballero.

It was June of 287 AC before Petyr next came into contact with House Jasper. He was on the docks of King’s Landing, investigating the harbor master for corruption on Jon Arryn’s orders, when to his surprise he found Edwin speaking with Lord Teddy Jasper, Ser Dolins, and Ser Darron. Petyr had the opportunity to remind House Jasper of their unpaid tax (20% the value of their dragon egg). In farewell he recommended they lodge at Chataya’s while in the city.

At The Spring Tourney of 288 AC Petyr approached Teddy in the grandstand. He explained he had treaveled back the Vale with Lord and Lady Arryn and that he was pleased to see Teddy. After some small talk Petyr suggested a bet on the final bout. Petyr wagered 5gd on Ser Leo, Teddy chose Ser Darron, and if Ser Argyle were to win it would be a push. Teddy left the tournament 5gd richer.