Short answers, pulled from the story.
The research paper titled Improving Language Understanding by Generative Pre-Training landed on the arXiv server on the 11th of June 2018. This document described GPT-1, the first model to successfully merge the transformer architecture with generative pre-training.
OpenAI responded with GPT-3 on the 28th of May 2020, a model boasting 175 billion parameters trained on a dataset far larger than anything seen before. This model demonstrated few-shot and zero-shot learning abilities, meaning it could perform complex tasks with only a few examples or even no examples at all.
The public chatbot named ChatGPT was launched by OpenAI on the 30th of November 2022. The model powering this chatbot was refined through reinforcement learning from human feedback, or RLHF, which involved human trainers engaging in conversations with the model to teach it how to follow instructions.
GPT-4 was released on the 14th of March 2023 as a multi-modal system capable of processing and generating text, images, and audio. This model could analyze charts, interpret diagrams, and generate code based on visual inputs, making it a versatile tool for a wide range of applications.
The 23rd of April 2023 marked the beginning of a legal and commercial battle over the term GPT, as OpenAI asserted that the acronym should be regarded as a brand of the company rather than a generic technical term. OpenAI applied to the United States Patent and Trademark Office to seek domestic trademark registration for the term GPT.